diff --git a/crates/erg_compiler/lib/external/certifi.d/__init__.d.er b/crates/erg_compiler/lib/external/certifi.d/__init__.d.er
new file mode 100644
index 00000000..868837c5
--- /dev/null
+++ b/crates/erg_compiler/lib/external/certifi.d/__init__.d.er
@@ -0,0 +1,3 @@
+.core = pyimport "./core"
+
+{.contents!; .where!} = .core
diff --git a/crates/erg_compiler/lib/external/certifi.d/core.d.er b/crates/erg_compiler/lib/external/certifi.d/core.d.er
new file mode 100644
index 00000000..e0921f98
--- /dev/null
+++ b/crates/erg_compiler/lib/external/certifi.d/core.d.er
@@ -0,0 +1,2 @@
+.contents!: () => Str
+.where!: () => Str
diff --git a/crates/erg_compiler/lib/external/certifi.d/package.er b/crates/erg_compiler/lib/external/certifi.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/erg_compiler.d/__init__.d.er b/crates/erg_compiler/lib/external/erg_compiler.d/__init__.d.er
new file mode 100644
index 00000000..506cc476
--- /dev/null
+++ b/crates/erg_compiler/lib/external/erg_compiler.d/__init__.d.er
@@ -0,0 +1,8 @@
+.erg_parser = pyimport "erg_parser"
+
+.compile: (code: Str, mode: Str) -> Code
+.compile_ast: (ast: .erg_parser.ast.AST, mode: Str) -> Code
+.compile_file: (path: Str) -> Code
+.exec: (code: Str) -> Module
+.exec_ast: (ast: .erg_parser.ast.AST) -> Module
+.__import__: (name: Str) -> Module
diff --git a/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/__init__.d.er b/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/__init__.d.er
new file mode 100644
index 00000000..f01d88a9
--- /dev/null
+++ b/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/__init__.d.er
@@ -0,0 +1,4 @@
+.ast = pyimport "./ast"
+.expr = pyimport "./expr"
+
+.parse: (code: Str) -> .ast.Module
diff --git a/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/ast.d.er b/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/ast.d.er
new file mode 100644
index 00000000..847f6135
--- /dev/null
+++ b/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/ast.d.er
@@ -0,0 +1,38 @@
+.Token: ClassType
+.TokenKind: ClassType
+
+.Literal: ClassType
+.VarName: ClassType
+.Identifier: ClassType
+.Attribute: ClassType
+.TupleAttribute: ClassType
+.Subscript: ClassType
+.TypeApp: ClassType
+.NormalArray: ClassType
+.NormalTuple: ClassType
+.NormalDict: ClassType
+.NormalSet: ClassType
+.NormalRecord: ClassType
+.BinOp: ClassType
+.UnaryOp: ClassType
+.Call: ClassType
+.Args: ClassType
+.Block: ClassType
+.DataPack: ClassType
+.Lambda: ClassType
+.TypeAscription: ClassType
+.VarSignature: ClassType
+.SubrSignature: ClassType
+.Def: ClassType
+.Methods: ClassType
+.ClassDef: ClassType
+.PatchDef: ClassType
+.ReDef: ClassType
+.Compound: ClassType
+.InlineModule: ClassType
+.Dummy: ClassType
+.Module: ClassType
+
+.AST: ClassType
+.AST.
+    new: (name: Str, mod: .Module) -> .AST
diff --git a/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/expr.d.er b/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/expr.d.er
new file mode 100644
index 00000000..7ce9abdf
--- /dev/null
+++ b/crates/erg_compiler/lib/external/erg_compiler.d/erg_parser.d/expr.d.er
@@ -0,0 +1,20 @@
+.Literal: ClassType
+.NormalArray: ClassType
+.NormalTuple: ClassType
+.NormalDict: ClassType
+.NormalSet: ClassType
+.NormalRecord: ClassType
+.BinOp: ClassType
+.UnaryOp: ClassType
+.Call: ClassType
+.DataPack: ClassType
+.Lambda: ClassType
+.TypeAscription: ClassType
+.Def: ClassType
+.Methods: ClassType
+.ClassDef: ClassType
+.PatchDef: ClassType
+.ReDef: ClassType
+.Compound: ClassType
+.InlineModule: ClassType
+.Dummy: ClassType
diff --git a/crates/erg_compiler/lib/external/erg_compiler.d/package.er b/crates/erg_compiler/lib/external/erg_compiler.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/idna.d/__init__.d.er b/crates/erg_compiler/lib/external/idna.d/__init__.d.er
new file mode 100644
index 00000000..23f1a656
--- /dev/null
+++ b/crates/erg_compiler/lib/external/idna.d/__init__.d.er
@@ -0,0 +1,18 @@
+.core = pyimport "./core"
+
+{
+    .alabel;
+    .check_bidi;
+    .check_hyphen_ok;
+    .check_initial_combiner;
+    .check_label;
+    .check_nfc;
+    .decode;
+    .encode;
+    .ulabel;
+    .uts46_remap;
+    .valid_contextj;
+    .valid_contexto;
+    .valid_label_length;
+    .valid_string_length;
+} = .core
diff --git a/crates/erg_compiler/lib/external/idna.d/core.d.er b/crates/erg_compiler/lib/external/idna.d/core.d.er
new file mode 100644
index 00000000..3d7ac0bf
--- /dev/null
+++ b/crates/erg_compiler/lib/external/idna.d/core.d.er
@@ -0,0 +1,33 @@
+.IDNAError: ClassType
+.IDNABidiError: ClassType
+.IDNABidiError <: .IDNAError
+.InvalidCodepoint: ClassType
+.InvalidCodepoint <: .IDNAError
+.InvalidCodepointContext: ClassType
+.InvalidCodepointContext <: .IDNAError
+
+.valid_label_length: (label: Str or Bytes) -> Bool
+.valid_string_length: (label: Str or Bytes, trailing_dot: Bool) -> Bool
+.check_bidi: (label: Str, check_ltr := Bool) -> Bool
+.check_initial_combiner: (label: Str) -> Bool
+.check_hyphen_ok: (label: Str) -> Bool
+.check_nfc: (label: Str) -> Bool
+.valid_contextj: (label: Str, pos: Int) -> Bool
+.valid_contexto: (label: Str, pos: Int, exception := Bool) -> Bool
+.check_label: (label: Str or Bytes) -> NoneType
+.alabel: (label: Str) -> Bytes
+.ulabel: (label: Str or Bytes) -> Str
+.uts46_remap: (domain: Str or Bytes, std3_rules := Bool, transitional := Bool) -> Str
+.encode: (
+    s: Str or Bytes,
+    strict:= Bool,
+    uts46:= Bool,
+    std3_rules:= Bool,
+    transitional:= Bool,
+) -> Bytes
+.decode: (
+    s: Str or Bytes,
+    strict:= Bool,
+    uts46:= Bool,
+    std3_rules:= Bool,
+) -> Str
diff --git a/crates/erg_compiler/lib/external/idna.d/package.er b/crates/erg_compiler/lib/external/idna.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/jinja2.d/__init__.d.er b/crates/erg_compiler/lib/external/jinja2.d/__init__.d.er
new file mode 100644
index 00000000..a2f8509c
--- /dev/null
+++ b/crates/erg_compiler/lib/external/jinja2.d/__init__.d.er
@@ -0,0 +1,26 @@
+.BaseLoader: ClassType
+
+.PackageLoader: ClassType
+.PackageLoader <: .BaseLoader
+.PackageLoader.
+    __call__: (package_name: Str, package_path: Str) -> .PackageLoader
+
+.FileSystemLoader: ClassType
+.FileSystemLoader <: .BaseLoader
+.FileSystemLoader.
+    __call__: (path: Str) -> .FileSystemLoader
+
+.DictLoader: ClassType
+.DictLoader <: .BaseLoader
+.DictLoader.
+    __call__: (mapping: {Str: Str}) -> .DictLoader
+
+.Template: ClassType
+.Template.
+    __call__: (source: Str, autoescape := Bool, enable_async := Bool) -> .Template
+    render: (self: Ref(.Template), **kwargs: Obj) -> Str
+
+.Enviroment: ClassType
+.Enviroment.
+    __call__: (loader := .BaseLoader, trim_blocks := Bool) -> .Enviroment
+    get_template: (self: Ref(.Enviroment), name := Str) -> .Template
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/__init__.d.er b/crates/erg_compiler/lib/external/matplotlib.d/__init__.d.er
new file mode 100644
index 00000000..9f76a154
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/__init__.d.er
@@ -0,0 +1,4 @@
+.pyplot = pyimport "./pyplot"
+.scale = pyimport "./scale"
+
+.use!: Str => NoneType
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/axes.d/__init__.d.er b/crates/erg_compiler/lib/external/matplotlib.d/axes.d/__init__.d.er
new file mode 100644
index 00000000..248d4124
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/axes.d/__init__.d.er
@@ -0,0 +1,3 @@
+._axes = pyimport "./_axes"
+
+.Axes! = ._axes.Axes!
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/axes.d/_axes.d.er b/crates/erg_compiler/lib/external/matplotlib.d/axes.d/_axes.d.er
new file mode 100644
index 00000000..d2a8cdb1
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/axes.d/_axes.d.er
@@ -0,0 +1,21 @@
+.Axes!: ClassType
+.Axes!.
+    scatter!: (
+        self: RefMut(.Axes!),
+        x: Num, # TODO: Float | ArrayLike
+        y: Num,
+        s := Num,
+        c := Iterable(Int),
+        vmin := Float,
+        vmax := Float,
+    ) => NoneType
+    set!: (
+        self: RefMut(.Axes!),
+        xlabel := Str,
+        xlim := (Float, Float),
+        xticks := Iterable(Obj),
+        ylabel := Str,
+        ylim := (Float, Float),
+        yticks := Iterable(Obj),
+        title := Str
+    ) => NoneType
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/figure.d.er b/crates/erg_compiler/lib/external/matplotlib.d/figure.d.er
new file mode 100644
index 00000000..38f0ccaf
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/figure.d.er
@@ -0,0 +1,5 @@
+axes = pyimport "./axes"
+
+.Figure!: ClassType
+.Figure!.
+    add_axes!: (self: RefMut(.Figure!), rect: [Nat; 4], projection := Str or NoneType, polar := Bool, label := Str) => axes.Axes!
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/image.d.er b/crates/erg_compiler/lib/external/matplotlib.d/image.d.er
new file mode 100644
index 00000000..4ff9ee29
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/image.d.er
@@ -0,0 +1,4 @@
+_ImageBase: ClassType
+
+.AxesImage!: ClassType
+.AxesImage! <: _ImageBase
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/legend.d.er b/crates/erg_compiler/lib/external/matplotlib.d/legend.d.er
new file mode 100644
index 00000000..f79972cd
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/legend.d.er
@@ -0,0 +1 @@
+.Legend: ClassType
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/lines.d.er b/crates/erg_compiler/lib/external/matplotlib.d/lines.d.er
new file mode 100644
index 00000000..85960617
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/lines.d.er
@@ -0,0 +1,2 @@
+.Line2D: ClassType
+.Line3D: ClassType
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/package.er b/crates/erg_compiler/lib/external/matplotlib.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/path.d.er b/crates/erg_compiler/lib/external/matplotlib.d/path.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/pyplot.d/__init__.d.er b/crates/erg_compiler/lib/external/matplotlib.d/pyplot.d/__init__.d.er
new file mode 100644
index 00000000..de5ed384
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/pyplot.d/__init__.d.er
@@ -0,0 +1,30 @@
+contextlib = pyimport "contextlib"
+
+# lines = pyimport "../lines"
+text = pyimport "../text"
+legend = pyimport "../legend"
+.style = pyimport "../style"
+figure = pyimport "../figure"
+axes = pyimport "../axes"
+image = pyimport "../image"
+
+.plot!: (*args: Obj, scaleX := Bool, scaleY := Bool) => [Obj; _]
+.imshow!: (X: Obj, cmap := Str, interpolation := Str) => image.AxesImage!
+.show!: () => NoneType
+.text!: (x: Float, y: Float, s: Str, fontdict := {Str: Obj}, fontsize := Nat) => text.Text
+.title!: (title: Str) => text.Text
+.xlabel!: (label: Str) => text.Text
+.ylabel!: (label: Str) => text.Text
+.xlim!: (left := Float, right := Float) => (Float, Float) \
+    and ((left_right: (Float, Float)) => (Float, Float))
+.ylim!: (bottom := Float, top := Float) => (Float, Float) \
+    and ((bottom_top: (Float, Float)) => (Float, Float))
+.legend!: (labels := [Str; _]) => legend.Legend
+.savefig!: (fname: Str, dpi := Float or Str, format := Str) => NoneType
+.subplots!: (() => (figure.Figure!, axes.Axes!)) \
+    and ((nrows: {1}, ncols: {1}) => (figure.Figure!, axes.Axes!)) \
+    and ((nrows: {1}, ncols: Nat) => (figure.Figure!, [axes.Axes!; _])) \
+    and ((nrows: Nat, ncols: {1}) => (figure.Figure!, [axes.Axes!; _])) \
+    and ((nrows: Nat, ncols: Nat) => (figure.Figure!, [[axes.Axes!; _]; _]))
+.figure!: (num := Int or Str, figsize := [Float; _], dpi := Float) => figure.Figure!
+.xkcd!: (scale := Float, length := Float, randomness := Float) => contextlib.ExitStack!
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/scale.d.er b/crates/erg_compiler/lib/external/matplotlib.d/scale.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/style.d/__init__.d.er b/crates/erg_compiler/lib/external/matplotlib.d/style.d/__init__.d.er
new file mode 100644
index 00000000..1cd37327
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/style.d/__init__.d.er
@@ -0,0 +1 @@
+.use!: Str => NoneType
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/testing.d/__init__.d.er b/crates/erg_compiler/lib/external/matplotlib.d/testing.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/matplotlib.d/text.d.er b/crates/erg_compiler/lib/external/matplotlib.d/text.d.er
new file mode 100644
index 00000000..50ea975f
--- /dev/null
+++ b/crates/erg_compiler/lib/external/matplotlib.d/text.d.er
@@ -0,0 +1 @@
+.Text: ClassType
diff --git a/crates/erg_compiler/lib/external/numpy.d/__init__.d.er b/crates/erg_compiler/lib/external/numpy.d/__init__.d.er
new file mode 100644
index 00000000..4a33c739
--- /dev/null
+++ b/crates/erg_compiler/lib/external/numpy.d/__init__.d.er
@@ -0,0 +1,89 @@
+.Complex64 = 'complex64': ClassType
+.Complex128 = 'complex128': ClassType
+
+.Float16 = 'float16': ClassType
+.Float32 = 'float32': ClassType
+.Float64 = 'float64': ClassType
+
+.Int8 = 'int8': ClassType
+.Int16 = 'int16': ClassType
+.Int32 = 'int32': ClassType
+.Int64 = 'int64': ClassType
+
+.UInt8 = 'uint8': ClassType
+.UInt16 = 'uint16': ClassType
+.UInt32 = 'uint32': ClassType
+.UInt64 = 'uint64': ClassType
+
+.Bool_ = 'bool_': ClassType
+.Str_ = 'str_': ClassType
+
+.NDArray = 'ndarray': (T: Type, Shape: [Nat; _]) -> ClassType
+.NDArray(T, _) <: Output T
+.NDArray(_, _) <: Num
+.NDArray(T, S)|<: Add .NDArray(T, S)|.
+    Output: {.NDArray(T, S)}
+    __add__: (self: .NDArray(T, S), other: .NDArray(T, S)) -> .NDArray(T, S)
+.NDArray(T, S)|<: Add T|.
+    Output: {.NDArray(T, S)}
+    __add__: (self: .NDArray(T, S), other: T) -> .NDArray(T, S)
+.NDArray(T, S)|<: Sub .NDArray(T, S)|.
+    Output: {.NDArray(T, S)}
+    __sub__: (self: .NDArray(T, S), other: .NDArray(T, S)) -> .NDArray(T, S)
+.NDArray(T, S)|<: Sub T|.
+    Output: {.NDArray(T, S)}
+    __sub__: (self: .NDArray(T, S), other: T) -> .NDArray(T, S)
+.NDArray(T, S)|<: Mul .NDArray(T, S)|.
+    Output: {.NDArray(T, S)}
+    __mul__: (self: .NDArray(T, S), other: .NDArray(T, S)) -> .NDArray(T, S)
+.NDArray(T, S)|<: Mul T|.
+    Output: {.NDArray(T, S)}
+    __mul__: (self: .NDArray(T, S), other: T) -> .NDArray(T, S)
+.NDArray(T, S)|<: Div .NDArray(T, S)|.
+    Output: {.NDArray(T, S)}
+    __div__: (self: .NDArray(T, S), other: .NDArray(T, S)) -> .NDArray(T, S)
+.NDArray(T, S)|<: Div T|.
+    Output: {.NDArray(T, S)}
+    __div__: (self: .NDArray(T, S), other: T) -> .NDArray(T, S)
+.NDArray.
+    shape: [Nat; _]
+    ndim: Nat
+    dtype: Type
+    size: Nat
+    copy: |T, S: [Nat; _]|(self: .NDArray(T, S),) -> .NDArray(T, S)
+    reshape: |T, Old: [Nat; _], S: {A: [Nat; _] | A.prod() == Old.prod()}|(
+        self: .NDArray(T, Old),
+        shape: {S},
+    ) -> .NDArray(T, S)
+    sum: |T <: Num|(self: .NDArray(T, _),) -> T
+    take: (|T|(self: .NDArray(T, _), indice: Nat) -> T) \
+        and (|T|(self: .NDArray(T, _), indices: .NDArray(Nat) or [Nat; _]) -> .NDArray(T, _))
+    tobytes: |T|(self: .NDArray(T, _),) -> Bytes
+    tolist: |T|(self: .NDArray(T, _),) -> [T; _]
+
+.nan: Float
+.Nan: Float
+
+.abs: |T, S: [Nat; _]|(object: .NDArray(T, S),) -> .NDArray(T, S)
+.add: |T, S: [Nat; _]|(object: .NDArray(T, S), other: .NDArray(T, S)) -> .NDArray(T, S)
+.all: |T <: Num|(object: .NDArray(T),) -> Bool
+.any: |T <: Num|(object: .NDArray(T),) -> Bool
+.arange: |T <: Num|(start: T, stop := T, step := T) -> .NDArray(T)
+.array: |T, S: [Nat; _]|(object: HasScalarType(T) and HasShape(S),) -> .NDArray(T, S)
+.linspace: |T <: Num|(start: T, stop: T, num := Nat, endpoint := Bool, retstep := Bool, dtype := Type, axis := Nat) -> .NDArray(T)
+.max: |T <: Num|(object: .NDArray(T),) -> T
+.mean: |T <: Num|(object: .NDArray(T),) -> T
+.min: |T <: Num|(object: .NDArray(T),) -> T
+.ones: |T|(shape: Nat or [Nat; _], dtype := Type) -> .NDArray(T)
+.reshapce: |T|(object: .NDArray(T), shape: [Nat; _]) -> .NDArray(T)
+.std: |T <: Num|(object: .NDArray(T),) -> T
+.sum: |T|(object: .NDArray(T),) -> T
+.sqrt: |T|(object: .NDArray(T),) -> .NDArray(T)
+.transpose: |T|(object: .NDArray(T), axes := [Nat; _]) -> .NDArray(T)
+.zeros: (|N: Nat|(shape: {N}, dtype := Type) -> .NDArray(Nat, [N])) \
+    and (|S: [Nat; _]|(shape: {S}, dtype := Type) -> .NDArray(Nat, S))
+.empty: (|N: Nat|(shape: {N}, dtype := Type) -> .NDArray(Nat, [N])) \
+    and (|S: [Nat; _]|(shape: {S}, dtype := Type) -> .NDArray(Nat, S))
+.dot: (|T, I: Nat, J: Nat, K: Nat|(l: .NDArray(T, [I, J]), r: .NDArray(T, [J, K])) -> .NDArray(T, [I, K])) \
+    and (|T, I: Nat, J: Nat|(l: .NDArray(T, [I]), r: .NDArray(T, [I, J])) -> .NDArray(T, [J])) \
+    and (|T, I: Nat|(l: .NDArray(T, [I]), r: .NDArray(T, [I])) -> T)
diff --git a/crates/erg_compiler/lib/external/numpy.d/fft.d/__init__.d.er b/crates/erg_compiler/lib/external/numpy.d/fft.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/numpy.d/lib.d/__init__.d.er b/crates/erg_compiler/lib/external/numpy.d/lib.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/numpy.d/linalg.d/__init__.d.er b/crates/erg_compiler/lib/external/numpy.d/linalg.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/numpy.d/package.er b/crates/erg_compiler/lib/external/numpy.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/numpy.d/polynomial.d/__init__.d.er b/crates/erg_compiler/lib/external/numpy.d/polynomial.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/numpy.d/random.d/__init__.d.er b/crates/erg_compiler/lib/external/numpy.d/random.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/packaging.d/__init__.d.er b/crates/erg_compiler/lib/external/packaging.d/__init__.d.er
new file mode 100644
index 00000000..cd8dd60d
--- /dev/null
+++ b/crates/erg_compiler/lib/external/packaging.d/__init__.d.er
@@ -0,0 +1 @@
+.version = pyimport "./version"
diff --git a/crates/erg_compiler/lib/external/packaging.d/package.er b/crates/erg_compiler/lib/external/packaging.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/packaging.d/version.d.er b/crates/erg_compiler/lib/external/packaging.d/version.d.er
new file mode 100644
index 00000000..e7138c3e
--- /dev/null
+++ b/crates/erg_compiler/lib/external/packaging.d/version.d.er
@@ -0,0 +1,23 @@
+.Version: ClassType
+.Version <: Eq
+.Version <: Ord
+.Version.
+    epoch: Nat
+    release: (Nat, Nat, Nat)
+    pre: (Str, Nat) or NoneType
+    post: Nat or NoneType
+    dev: Nat or NoneType
+    local: Str or NoneType
+    public: Str
+    base_version: Str
+    is_prerelease: Bool
+    is_postrelease: Bool
+    is_devrelease: Bool
+    major: Nat
+    minor: Nat
+    micro: Nat
+    __call__: (ver: Str) -> .Version
+
+.InvalidVersion: ClassType
+
+.parse: (ver: Str) -> .Version
diff --git a/crates/erg_compiler/lib/external/pandas.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/__init__.d.er
new file mode 100644
index 00000000..26b0275f
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/__init__.d.er
@@ -0,0 +1,17 @@
+.core = pyimport "core"
+.io = pyimport "io"
+.plotting = pyimport "plotting"
+.util = pyimport "util"
+
+{
+    .DataFrame!;
+    .Series!;
+    .Index;
+} = pyimport "core/api"
+
+{
+    .read_csv!;
+} = pyimport "io/parsers"
+{
+    .read_json!;
+} = pyimport "io/json"
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/__init__.d.er
new file mode 100644
index 00000000..148c5f09
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/core.d/__init__.d.er
@@ -0,0 +1,5 @@
+.algorithms = pyimport "algorithms"
+.api = pyimport "api"
+.frame = pyimport "frame"
+.indexes = pyimport "indexes"
+.series = pyimport "series"
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/algorithms.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/algorithms.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/api.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/api.d.er
new file mode 100644
index 00000000..12a21038
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/core.d/api.d.er
@@ -0,0 +1,3 @@
+{.DataFrame!;} = pyimport "./frame"
+{.Series!;} = pyimport "./series"
+{.Index;} = pyimport "./indexes/api"
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/frame.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/frame.d.er
new file mode 100644
index 00000000..916e8475
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/core.d/frame.d.er
@@ -0,0 +1,14 @@
+{.Index;} = pyimport "./indexes/api"
+
+# I := Nat, V := Obj
+.DataFrame!: (C: Type, I: Type, V: Type) -> ClassType
+.DataFrame!(C, I, V) <: Input(C)
+.DataFrame!(C, I, V) <: Input(I)
+.DataFrame!(C, I, V) <: Output(V)
+.DataFrame!.
+    __call__: |K, V, I|(dic: {K: [V; _]} or Iterable(Iterable(V)), index: [I; _] := [Nat; _]) -> .DataFrame!(K, I, V)
+    shape: (Nat, Nat)
+    index: .Index(_) # TODO
+    head: |C, I, V|(self: .DataFrame!(C, I, V), tail: Nat := {5}) -> .DataFrame!(C, I, V)
+    tail: |C, I, V|(self: .DataFrame!(C, I, V), tail: Nat := {5}) -> .DataFrame!(C, I, V)
+    info!: (self: .DataFrame!(_, _, _)) => NoneType
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/api.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/api.d.er
new file mode 100644
index 00000000..8d9b2d3f
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/api.d.er
@@ -0,0 +1 @@
+{.Index;} = pyimport "./base"
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/base.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/base.d.er
new file mode 100644
index 00000000..18772ade
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/core.d/indexes.d/base.d.er
@@ -0,0 +1,2 @@
+.Index: (T: Type) -> ClassType
+.Index(T) <: Output(T)
diff --git a/crates/erg_compiler/lib/external/pandas.d/core.d/series.d.er b/crates/erg_compiler/lib/external/pandas.d/core.d/series.d.er
new file mode 100644
index 00000000..8466314e
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/core.d/series.d.er
@@ -0,0 +1,8 @@
+{.Index;} = pyimport "./indexes/api"
+
+# K := Nat, V := Obj
+.Series!: (K: Type, V: Type) -> ClassType
+.Series!(K, V) <: Input(K)
+.Series!(K, V) <: Output(V)
+.Series!.
+    __call__: |K, V|(iterable: Iterable(V), index: [K; _] or .Index(K) := [Nat; _]) -> .Series! K, V
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/__init__.d.er
new file mode 100644
index 00000000..70a55393
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/io.d/__init__.d.er
@@ -0,0 +1,7 @@
+.api = pyimport "api"
+.clipboads = pyimport "clipboards"
+.common = pyimport "common"
+.excel = pyimport "excel"
+.html = pyimport "html"
+.json = pyimport "json"
+.parsers = pyimport "parsers"
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/api.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/api.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/clipboards.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/clipboards.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/common.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/common.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/excel.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/excel.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/html.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/html.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/json.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/json.d/__init__.d.er
new file mode 100644
index 00000000..6dfb3249
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/io.d/json.d/__init__.d.er
@@ -0,0 +1,3 @@
+{DataFrame!;} = pyimport "../../core/frame"
+
+.read_json!: (path: PathLike) => DataFrame!
diff --git a/crates/erg_compiler/lib/external/pandas.d/io.d/parsers.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/io.d/parsers.d/__init__.d.er
new file mode 100644
index 00000000..d6b73420
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/io.d/parsers.d/__init__.d.er
@@ -0,0 +1,3 @@
+{DataFrame!;} = pyimport "../../core/frame"
+
+.read_csv!: (path: PathLike) => DataFrame!
diff --git a/crates/erg_compiler/lib/external/pandas.d/package.er b/crates/erg_compiler/lib/external/pandas.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/plotting.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/plotting.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/pandas.d/util.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/util.d/__init__.d.er
new file mode 100644
index 00000000..3de8d778
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/util.d/__init__.d.er
@@ -0,0 +1 @@
+.version = pyimport "version"
diff --git a/crates/erg_compiler/lib/external/pandas.d/util.d/version.d/__init__.d.er b/crates/erg_compiler/lib/external/pandas.d/util.d/version.d/__init__.d.er
new file mode 100644
index 00000000..61d5bf11
--- /dev/null
+++ b/crates/erg_compiler/lib/external/pandas.d/util.d/version.d/__init__.d.er
@@ -0,0 +1 @@
+.Version: ClassType
diff --git a/crates/erg_compiler/lib/external/requests.d/__init__.d.er b/crates/erg_compiler/lib/external/requests.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/requests.d/package.er b/crates/erg_compiler/lib/external/requests.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/cluster.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/cluster.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/constants.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/constants.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/fftpack.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/fftpack.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/integrate.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/integrate.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/interpolate.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/interpolate.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/io.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/io.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/linalg.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/linalg.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/ndimage.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/ndimage.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/odr.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/odr.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/optimize.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/optimize.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/package.er b/crates/erg_compiler/lib/external/scipy.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/signal.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/signal.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/sparse.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/sparse.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/special.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/special.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/scipy.d/stats.d/__init__.d.er b/crates/erg_compiler/lib/external/scipy.d/stats.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/setuptools.d/__init__.d.er b/crates/erg_compiler/lib/external/setuptools.d/__init__.d.er
new file mode 100644
index 00000000..c9611432
--- /dev/null
+++ b/crates/erg_compiler/lib/external/setuptools.d/__init__.d.er
@@ -0,0 +1 @@
+.setup!: (*Obj,) => NoneType
diff --git a/crates/erg_compiler/lib/external/setuptools.d/command.d/develop.d.er b/crates/erg_compiler/lib/external/setuptools.d/command.d/develop.d.er
new file mode 100644
index 00000000..05902313
--- /dev/null
+++ b/crates/erg_compiler/lib/external/setuptools.d/command.d/develop.d.er
@@ -0,0 +1,3 @@
+.Develop = 'develop': ClassType
+.Develop.
+    run!: (self: .Develop) => NoneType
diff --git a/crates/erg_compiler/lib/external/setuptools.d/command.d/install.d.er b/crates/erg_compiler/lib/external/setuptools.d/command.d/install.d.er
new file mode 100644
index 00000000..d8294f5b
--- /dev/null
+++ b/crates/erg_compiler/lib/external/setuptools.d/command.d/install.d.er
@@ -0,0 +1,3 @@
+.Install = 'install': ClassType
+.Install.
+    run!: (self: .Install) => NoneType
diff --git a/crates/erg_compiler/lib/external/setuptools.d/package.er b/crates/erg_compiler/lib/external/setuptools.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/six.d/__init__.d.er b/crates/erg_compiler/lib/external/six.d/__init__.d.er
new file mode 100644
index 00000000..9034c3b3
--- /dev/null
+++ b/crates/erg_compiler/lib/external/six.d/__init__.d.er
@@ -0,0 +1,13 @@
+.PY2: Bool
+.PY3: Bool
+
+.class_types: [Type; _]
+.intger_types: [Type; _]
+.string_types: [Type; _]
+.float_types: [Type; _]
+.text_type: Type
+.binary_type: Type
+.MAXSIZE: Nat
+
+.exec_!: (code: Str, globals := {Str: Obj}, locals := {Str: Obj}) => Obj
+.print_!: (*objs: [Obj; _], end := Str, sep := Str) => NoneType
diff --git a/crates/erg_compiler/lib/external/six.d/package.er b/crates/erg_compiler/lib/external/six.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/torch.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/__init__.d.er
new file mode 100644
index 00000000..7d651819
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/__init__.d.er
@@ -0,0 +1,87 @@
+np = pyimport "numpy"
+
+.backends = pyimport "./backends"
+.cuda = pyimport "./cuda"
+.nn = pyimport "./nn"
+.optim = pyimport "./optim"
+.serialization = pyimport "./serialization"
+.utils = pyimport "./utils"
+
+{.load!; .save!;} = pyimport "./serialization"
+{.manual_seed!;} = pyimport "./random"
+{.no_grad;} = pyimport "./autograd"
+
+.Device = 'device': ClassType
+.device: (type: Str) => .Device
+
+.DType = 'dtype': ClassType
+.dtype: (type: Str) => .DType
+
+.UInt8 = 'uint8': ClassType
+.Int8  = 'int8': ClassType
+.Int16 = 'int16': ClassType
+.Int32 = 'int32': ClassType
+.Int64 = 'int64': ClassType
+.Float16 = 'float16': ClassType
+.Float32 = 'float32': ClassType
+.Float64 = 'float64': ClassType
+.Complex32 = 'complex32': ClassType
+.Complex64 = 'complex64': ClassType
+.Complex128 = 'complex128': ClassType
+
+.Size: (S: [Nat; _]) -> ClassType
+.Size(S).
+    __call__: (size: {S}) -> .Size(S)
+.Size(S)|<: Eq|.
+    __eq__: (self: .Size(S), other: .Size(S)) -> Bool
+.Tensor!: (T: Type, Shape: [Nat; _]) -> ClassType
+.Tensor!(T, _) <: Output T
+.Tensor!(T, S)|<: IrregularEq|.
+    Output: {Tensor!(Bool, S)}
+    __eq__: (self: .Tensor!(T, S), other: .Tensor!(T, S)) -> .Tensor!(Bool, S)
+.Tensor!(T, S)|<: Indexable(Nat, .Tensor!(T, _))|.
+    __getitem__: (self: .Tensor!(T, S), index: Nat or [Nat; _]) -> .Tensor!(T, _)
+.Tensor!(T, S).
+    data: .Tensor!(T, S)
+    shape: .Size(S)
+.Tensor!(_, _).
+    dtype: .DType
+    clone: |T, S: [Nat; _]|(self: .Tensor!(T, S)) -> .Tensor!(T, S)
+    cpu: |T, S: [Nat; _]|(self: .Tensor!(T, S)) -> .Tensor!(T, S)
+    detach: |T, S: [Nat; _]|(self: .Tensor!(T, S)) -> .Tensor!(T, S)
+    numpy: |T, S: [Nat; _]|(self: .Tensor!(T, S)) -> np.NDArray(T, S)
+    view: (|T, Old: [Nat; _], S: {A: [Nat; _] | A.prod() == Old.prod()}|(
+        self: .Tensor!(T, Old),
+        shape: {S},
+    ) -> .Tensor!(T, S)) \
+        and (|T|(self: .Tensor!(T, _), shape: [Int; _]) -> .Tensor!(T, _))
+    backward!: |T, S: [Nat; _]|(
+        self: RefMut(.Tensor!(T, S)),
+        gradient := .Tensor!(T, S),
+        retain_graph := Bool,
+        create_graph := Bool,
+    ) => NoneType
+    # TODO: S bound
+    item: |T|(self: Ref .Tensor!(T, _)) -> T
+    to: (|T, S: [Nat; _]|(
+        self: .Tensor!(T, S),
+        other: .DType or .Device,
+        non_blocking := Bool,
+        copy := Bool,
+    ) -> .Tensor!(T, S))
+    size: (|T, S: [Nat; _]|(self: .Tensor!(T, S), dim: Nat) -> Nat) \
+        and (|T, S: [Nat; _]|(self: .Tensor!(T, S)) -> .Size)
+    sum: |T, S: [Nat; _]|(self: .Tensor!(T, S)) -> .Tensor!(T, [])
+    squeeze: (|T, S: [Nat; _]|(self: .Tensor!(T, S)) -> .Tensor!(T, S.remove_all(1))) \
+        and (|T|(self: .Tensor!(T, _)) -> .Tensor!(T, _))
+    unsqueeze: (|T, S: [Nat; _], Dim: Nat|(self: .Tensor!(T, S), dim: {Dim}) -> .Tensor!(T, S.insert(Dim, 1))) \
+        and (|T|(self: .Tensor!(T, _), dim: Nat) -> .Tensor!(T, _))
+
+.relu: |T, S: [Nat; _]|(x: .Tensor!(T, S)) -> .Tensor!(T, S)
+.softmax: |T, S: [Nat; _]|(x: .Tensor!(T, S), dim: Nat) -> .Tensor!(T, S)
+.max: (|T|(input: .Tensor!(T, _), dim: Nat, keepdim := Bool) -> (.Tensor!(T, _)), .Tensor!(T, _)) \
+    and (|T|(input: .Tensor!(T, _)) -> .Tensor!(T, _))
+.min: (|T|(input: .Tensor!(T, _), dim: Nat, keepdim := Bool) -> (.Tensor!(T, _)), .Tensor!(T, _)) \
+    and (|T|(input: .Tensor!(T, _)) -> .Tensor!(T, _))
+.tensor: (|T, S: [Nat; _]|(data: HasScalarType(T) and HasShape(S), dtype := .DType, device := .Device) -> .Tensor!(T, S)) \
+    and (|T|(data: [T; _], dtype := .DType, device := .Device) -> .Tensor!(T, _))
diff --git a/crates/erg_compiler/lib/external/torch.d/autograd.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/autograd.d/__init__.d.er
new file mode 100644
index 00000000..d199091f
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/autograd.d/__init__.d.er
@@ -0,0 +1 @@
+{.no_grad;} = import "./grad_mode"
diff --git a/crates/erg_compiler/lib/external/torch.d/autograd.d/grad_mode.d.er b/crates/erg_compiler/lib/external/torch.d/autograd.d/grad_mode.d.er
new file mode 100644
index 00000000..94019a0d
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/autograd.d/grad_mode.d.er
@@ -0,0 +1,3 @@
+.NoGrad = 'no_grad': ClassType
+.NoGrad <: ContextManager
+.no_grad: () -> .NoGrad
diff --git a/crates/erg_compiler/lib/external/torch.d/backends.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/backends.d/__init__.d.er
new file mode 100644
index 00000000..93d960ec
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/backends.d/__init__.d.er
@@ -0,0 +1 @@
+.mps = pyimport "./mps"
diff --git a/crates/erg_compiler/lib/external/torch.d/backends.d/mps.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/backends.d/mps.d/__init__.d.er
new file mode 100644
index 00000000..ce367723
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/backends.d/mps.d/__init__.d.er
@@ -0,0 +1 @@
+.is_available!: () => Bool
diff --git a/crates/erg_compiler/lib/external/torch.d/cuda.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/cuda.d/__init__.d.er
new file mode 100644
index 00000000..ce367723
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/cuda.d/__init__.d.er
@@ -0,0 +1 @@
+.is_available!: () => Bool
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/__init__.d.er
new file mode 100644
index 00000000..21f8d8bc
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/__init__.d.er
@@ -0,0 +1,17 @@
+.modules = pyimport "./modules"
+.parameter = pyimport "./parameter"
+
+{
+    .Conv1d;
+    .Conv2d;
+    .Conv3d;
+    .CrossEntropyLoss;
+    .Flatten;
+    .Linear;
+    .MaxPool1d;
+    .MaxPool2d;
+    .MaxPool3d;
+    .Module;
+    .ReLU;
+} = .modules
+{.Parameter;} = .parameter
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/__init__.d.er
new file mode 100644
index 00000000..ac605c73
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/__init__.d.er
@@ -0,0 +1,17 @@
+.activation = pyimport "./activation"
+.container = pyimport "./container"
+.conv = pyimport "./conv"
+.flatten = pyimport "./flatten"
+.linear = pyimport "./linear"
+.loss = pyimport "./loss"
+.module = pyimport "./module"
+.pooling = pyimport "./pooling"
+
+{.ReLU;} = .activation
+{.Sequential;} = .container
+{.Conv1d; .Conv2d; .Conv3d;} = .conv
+{.Flatten;} = .flatten
+{.Linear;} = .linear
+{.CrossEntropyLoss;} = .loss
+{.Module;} = .module
+{.MaxPool1d; .MaxPool2d; .MaxPool3d;} = .pooling
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/activation.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/activation.d.er
new file mode 100644
index 00000000..27ea8ecc
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/activation.d.er
@@ -0,0 +1,10 @@
+{Tensor!;} = pyimport "torch"
+
+.ReLU: ClassType
+.ReLU.
+    __call__: () -> .ReLU
+.ReLU|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .ReLU,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/container.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/container.d.er
new file mode 100644
index 00000000..48001090
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/container.d.er
@@ -0,0 +1,11 @@
+{Tensor!;} = pyimport "torch"
+{Module;} = pyimport "torch/nn"
+
+.Sequential: ClassType
+.Sequential.
+    __call__: (*args: Module) -> .Sequential
+.Sequential|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .Sequential,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/conv.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/conv.d.er
new file mode 100644
index 00000000..813d73ad
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/conv.d.er
@@ -0,0 +1,71 @@
+{Device; DType; Tensor!;} = pyimport "torch"
+{Module;} = pyimport "torch/nn"
+
+_ConvNd: ClassType
+_ConvNd <: Module
+
+.Conv1d: ClassType
+.Conv1d <: _ConvNd
+.Conv1d.
+    __call__: (
+        in_channels: Nat,
+        out_channels: Nat,
+        kernel_size: Nat or [Nat; 1] or (Nat,),
+        stride := Nat or [Nat; 1] or (Nat,),
+        padding := Str or Nat or [Nat; 1] or (Nat,),
+        dilation := Nat or [Nat; 1] or (Nat,),
+        groups := Nat,
+        bias := Bool,
+        padding_mode := Str,
+        device := Device or Str or Nat,
+        dtype := DType or Str,
+    ) -> .Conv1d
+.Conv1d|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .Conv1d,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
+
+.Conv2d: ClassType
+.Conv2d <: _ConvNd
+.Conv2d.
+    __call__: (
+        in_channels: Nat,
+        out_channels: Nat,
+        kernel_size: Nat or [Nat; 2] or (Nat, Nat),
+        stride := Nat or [Nat; 2] or (Nat, Nat),
+        padding := Str or Nat or [Nat; 2] or (Nat, Nat),
+        dilation := Nat or [Nat; 2] or (Nat, Nat),
+        groups := Nat,
+        bias := Bool,
+        padding_mode := Str,
+        device := Device or Str or Nat,
+        dtype := DType or Str,
+    ) -> .Conv2d
+.Conv2d|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .Conv2d,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
+
+.Conv3d: ClassType
+.Conv3d <: _ConvNd
+.Conv3d.
+    __call__: (
+        in_channels: Nat,
+        out_channels: Nat,
+        kernel_size: Nat or [Nat; 3] or (Nat, Nat, Nat),
+        stride := Nat or [Nat; 3] or (Nat, Nat, Nat),
+        padding := Str or Nat or [Nat; 3] or (Nat, Nat, Nat),
+        dilation := Nat or [Nat; 3] or (Nat, Nat, Nat),
+        groups := Nat,
+        bias := Bool,
+        padding_mode := Str,
+        device := Device or Str or Nat,
+        dtype := DType or Str,
+    ) -> .Conv3d
+.Conv3d|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .Conv3d,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/flatten.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/flatten.d.er
new file mode 100644
index 00000000..ce76673c
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/flatten.d.er
@@ -0,0 +1,10 @@
+{Tensor!;} = pyimport "torch"
+
+.Flatten: ClassType
+.Flatten.
+    __call__: (start_dim: Nat, end_dim: Int) -> .Flatten
+.Flatten|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .Flatten,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/linear.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/linear.d.er
new file mode 100644
index 00000000..fd022bfc
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/linear.d.er
@@ -0,0 +1,18 @@
+{Module;} = pyimport "torch/nn"
+{Device; DType; Tensor!;} = pyimport "torch"
+
+.Linear: ClassType
+.Linear <: Module
+.Linear.
+    __call__: (
+        in_features: Nat,
+        out_features: Nat,
+        bias := Bool,
+        device := Device or Str or Nat,
+        dtype := DType or Str,
+    ) -> .Linear
+.Linear|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .Linear,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/loss.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/loss.d.er
new file mode 100644
index 00000000..1348a308
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/loss.d.er
@@ -0,0 +1,27 @@
+{Tensor!;} = pyimport "torch"
+{Module;} = pyimport "torch/nn"
+
+_Loss: ClassType
+_Loss <: Module
+_Loss.
+    reduction: Str
+
+_WeightedLoss: ClassType
+_WeightedLoss <: _Loss
+
+.CrossEntropyLoss: ClassType
+.CrossEntropyLoss <: _WeightedLoss
+.CrossEntropyLoss.
+    __call__: () -> .CrossEntropyLoss
+.CrossEntropyLoss|<: GenericCallable|.
+    __call__: |T|(
+        self: .CrossEntropyLoss,
+        input: Tensor!(T, _),
+        target: Tensor!(T, _),
+    ) -> Tensor!(T, [])
+.CrossEntropyLoss.
+    forward: |T|(
+        self: .CrossEntropyLoss,
+        input: Tensor!(T, _),
+        target: Tensor!(T, _),
+    ) -> Tensor!(T, [])
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/module.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/module.d.er
new file mode 100644
index 00000000..49b0ef6c
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/module.d.er
@@ -0,0 +1,43 @@
+{Tensor!;} = pyimport "torch"
+{Parameter;} = pyimport "torch/nn/parameter"
+
+.Module: ClassType
+.Module <: InheritableType
+.Module|<: GenericCallable|.
+    __call__: |T|(
+        self: .Module,
+        input: Tensor!(T, _),
+    ) -> Tensor!(T, _)
+.Module.
+    __init__: (self: RefMut(.Module)) => NoneType
+    parameters: (self: Ref(.Module), recurse := Bool) -> Iterator Parameter
+    named_parameters: (self: Ref(.Module), prefix := Str, recurse := Bool, remove_duplicate := Bool) -> Iterator((Str, Parameter))
+    # buffers: (self: Ref(.Module), recurse := Bool) -> Iterator .Tensor!
+    # named_buffers: (self: Ref(.Module), prefix := Str, recurse := Bool, remove_duplicate := Bool) -> Iterator((Str, .Tensor!))
+    children: (self: Ref(.Module)) -> Iterator .Module
+    named_children: (self: Ref(.Module), prefix := Str) -> Iterator((Str, .Module))
+    modules: (self: Ref(.Module)) -> Iterator .Module
+    named_modules: (self: Ref(.Module), memo := {.Module; _}, prefix := Str, remove_duplicate := Bool) -> Iterator((Str, .Module))
+    train: |T <: .Module|(self: Ref(T), mode := Bool) -> T
+    eval: |T <: .Module|(self: Ref(T)) -> T
+    zero_grad!: (self: RefMut(.Module), set_to_none := Bool) => NoneType
+    compile: (self: Ref(.Module), *args: Obj, **kwargs: Obj) -> .Module
+    # register_buffer!: (self: RefMut(.Module), name: Str, tensor := Tensor!, persistent := Bool) => NoneType
+    register_parameter!: (self: RefMut(.Module), name: Str, param := Parameter) => NoneType
+    add_module!: (self: RefMut(.Module), name: Str, module := .Module) => NoneType
+    register_module!: (self: RefMut(.Module), name: Str, module := .Module) => NoneType
+    get_submodule: (self: Ref(.Module), name: Str) -> .Module
+    get_parameter: (self: Ref(.Module), name: Str) -> Parameter
+    # get_buffer: (self: Ref(.Module), name: Str) -> .Tensor!
+    get_extra_state: (self: Ref(.Module)) -> Obj
+    set_extra_state!: (self: RefMut(.Module), state: Obj) => NoneType
+    apply!: |T <: .Module|(self: T, fn: (module: RefMut(T)) => NoneType) => T
+    cuda!: |T <: .Module|(self: T, device := Int) => T
+    ipu!: |T <: .Module|(self: T, device := Int) => T
+    xpu!: |T <: .Module|(self: T, device := Int) => T
+    cpu!: |T <: .Module|(self: T) => T
+    float: |T <: .Module|(self: T) -> T
+    double: |T <: .Module|(self: T) -> T
+    half: |T <: .Module|(self: T) -> T
+    bfloat16: |T <: .Module|(self: T) -> T
+    to: |T <: .Module|(self: T, *args: Obj, **kwargs: Obj) -> T
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/pooling.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/pooling.d.er
new file mode 100644
index 00000000..5296db7d
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/modules.d/pooling.d.er
@@ -0,0 +1,57 @@
+{Tensor!;} = pyimport "torch"
+{Module;} = pyimport "torch/nn"
+
+_MaxPoolNd: ClassType
+_MaxPoolNd <: Module
+
+.MaxPool1d: ClassType
+.MaxPool1d <: _MaxPoolNd
+.MaxPool1d <: GenericCallable
+.MaxPool1d.
+    __call__: (
+        kernel_size: Nat or [Nat; 1] or (Nat,),
+        stride := Nat or [Nat; 1] or (Nat,),
+        padding := Str or Nat or [Nat; 1] or (Nat,),
+        dilation := Nat or [Nat; 1] or (Nat,),
+        return_indices := Bool,
+        ceil_mode := Bool,
+    ) -> .MaxPool1d
+.MaxPool1d|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .MaxPool1d,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
+
+.MaxPool2d: ClassType
+.MaxPool2d <: _MaxPoolNd
+.MaxPool2d.
+    __call__: (
+        kernel_size: Nat or [Nat; 2] or (Nat, Nat),
+        stride := Nat or [Nat; 2] or (Nat, Nat),
+        padding := Str or Nat or [Nat; 2] or (Nat, Nat),
+        dilation := Nat or [Nat; 2] or (Nat, Nat),
+        return_indices := Bool,
+        ceil_mode := Bool,
+    ) -> .MaxPool2d
+.MaxPool2d|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .MaxPool2d,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
+
+.MaxPool3d: ClassType
+.MaxPool3d <: _MaxPoolNd
+.MaxPool3d.
+    __call__: (
+        kernel_size: Nat or [Nat; 3] or (Nat, Nat, Nat),
+        stride := Nat or [Nat; 3] or (Nat, Nat, Nat),
+        padding := Str or Nat or [Nat; 3] or (Nat, Nat, Nat),
+        dilation := Nat or [Nat; 3] or (Nat, Nat, Nat),
+        return_indices := Bool,
+        ceil_mode := Bool,
+    ) -> .MaxPool3d
+.MaxPool3d|<: GenericCallable|.
+    __call__: |T, S: [Nat; _]|(
+        self: .MaxPool3d,
+        input: Tensor!(T, S),
+    ) -> Tensor!(T, S)
diff --git a/crates/erg_compiler/lib/external/torch.d/nn.d/parameter.d.er b/crates/erg_compiler/lib/external/torch.d/nn.d/parameter.d.er
new file mode 100644
index 00000000..44a746a5
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/nn.d/parameter.d.er
@@ -0,0 +1 @@
+.Parameter: ClassType
diff --git a/crates/erg_compiler/lib/external/torch.d/optim.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/optim.d/__init__.d.er
new file mode 100644
index 00000000..7f17ee7d
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/optim.d/__init__.d.er
@@ -0,0 +1,47 @@
+{Parameter;} = pyimport "torch/nn/parameter"
+
+.Optimizer!: ClassType
+.Optimizer! <: InheritableType
+.Optimizer!.
+    __call__: (params: Iterable(Parameter)) -> .Optimizer!
+    zero_grad!: (self: RefMut .Optimizer!) => NoneType
+    step!: (self: RefMut .Optimizer!) => NoneType
+
+.ASGD!: ClassType
+.ASGD! <: .Optimizer!
+.Adadelta!: ClassType
+.Adadelta! <: .Optimizer!
+.Adagrad!: ClassType
+.Adagrad! <: .Optimizer!
+.Adam!: ClassType
+.Adam! <: .Optimizer!
+.Adam!.
+    __call__: (
+        params: Iterable(Parameter),
+        lr := Float,
+        betas := (Float, Float),
+        eps := Float,
+        weight_decay := Float,
+        amsgrad := Bool,
+        foreach := Bool,
+        maximize := Bool,
+    ) -> .Adam!
+
+.AdamW!: ClassType
+.AdamW! <: .Optimizer!
+.Adamax!: ClassType
+.Adamax! <: .Optimizer!
+.LBFGS!: ClassType
+.LBFGS! <: .Optimizer!
+.NAdam!: ClassType
+.NAdam! <: .Optimizer!
+.RAdam!: ClassType
+.RAdam! <: .Optimizer!
+.RMSprop!: ClassType
+.RMSprop! <: .Optimizer!
+.Rprop!: ClassType
+.Rprop! <: .Optimizer!
+.SGD!: ClassType
+.SGD! <: .Optimizer!
+.SparseAdam!: ClassType
+.SparseAdam! <: .Optimizer!
diff --git a/crates/erg_compiler/lib/external/torch.d/package.er b/crates/erg_compiler/lib/external/torch.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/torch.d/random.d.er b/crates/erg_compiler/lib/external/torch.d/random.d.er
new file mode 100644
index 00000000..a14eee54
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/random.d.er
@@ -0,0 +1 @@
+.manual_seed!: (seed: Int) => Obj
diff --git a/crates/erg_compiler/lib/external/torch.d/serialization.d.er b/crates/erg_compiler/lib/external/torch.d/serialization.d.er
new file mode 100644
index 00000000..e93871d0
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/serialization.d.er
@@ -0,0 +1,2 @@
+.load!: (f: PathLike) => NoneType
+.save!: (obj: Obj, f: PathLike) => NoneType
diff --git a/crates/erg_compiler/lib/external/torch.d/utils.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/utils.d/__init__.d.er
new file mode 100644
index 00000000..e794c7cc
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/utils.d/__init__.d.er
@@ -0,0 +1 @@
+.data = pyimport "./data"
diff --git a/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/__init__.d.er b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/__init__.d.er
new file mode 100644
index 00000000..19dba52c
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/__init__.d.er
@@ -0,0 +1,9 @@
+{.DataLoader;} = pyimport "./dataloader"
+{.Dataset;} = pyimport "./dataset"
+{
+    .Sampler;
+    .SequentialSampler;
+    .RandomSampler;
+    .SubsetRandomSampler;
+    .WeightedRandomSampler;
+} = pyimport "./sampler"
diff --git a/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/dataloader.d.er b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/dataloader.d.er
new file mode 100644
index 00000000..f1ebf2a3
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/dataloader.d.er
@@ -0,0 +1,25 @@
+torch = pyimport "torch"
+dataset = pyimport "./dataset"
+{Sampler;} = pyimport "./sampler"
+
+.DataLoader: ClassType
+.DataLoader <: Iterable((torch.Tensor!(_, _), torch.Tensor!(_, _)))
+.DataLoader.
+    __call__: (
+        dataset: dataset.Dataset,
+        batch_size := Nat,
+        shuffle := Bool,
+        sampler := Sampler,
+        batch_sampler := Sampler,
+        num_workers := Nat,
+        collate_fn := Obj,
+        pin_memory := Bool,
+        drop_last := Bool,
+        timeout := Float,
+        worker_init_fn := Obj,
+        multiprocessing_context := Obj,
+        generator := Obj,
+        prefetch_factor := Nat,
+        persistent_workers := Bool,
+        pin_memory_device := Str,
+    ) -> .DataLoader
diff --git a/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/dataset.d.er b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/dataset.d.er
new file mode 100644
index 00000000..a7c90009
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/dataset.d.er
@@ -0,0 +1 @@
+.Dataset: ClassType
diff --git a/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/sampler.d.er b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/sampler.d.er
new file mode 100644
index 00000000..d3d23665
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torch.d/utils.d/data.d/sampler.d.er
@@ -0,0 +1,13 @@
+.Sampler: ClassType
+
+.RandomSampler: ClassType
+.RandomSampler <: .Sampler
+
+.SequentialSampler: ClassType
+.SequentialSampler <: .Sampler
+
+.SubsetRandomSampler: ClassType
+.SubsetRandomSampler <: .Sampler
+
+.WeightedRandomSampler: ClassType
+.WeightedRandomSampler <: .Sampler
diff --git a/crates/erg_compiler/lib/external/torchvision.d/__init__.d.er b/crates/erg_compiler/lib/external/torchvision.d/__init__.d.er
new file mode 100644
index 00000000..e08f18c0
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/__init__.d.er
@@ -0,0 +1,2 @@
+.datasets = pyimport "./datasets"
+.transforms = pyimport "./transforms"
diff --git a/crates/erg_compiler/lib/external/torchvision.d/datasets.d/__init__.d.er b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/__init__.d.er
new file mode 100644
index 00000000..2f310273
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/__init__.d.er
@@ -0,0 +1,7 @@
+.cifar = pyimport "./cifar"
+.mnist = pyimport "./mnist"
+.utils = pyimport "./utils"
+.vision = pyimport "./vision"
+
+{.CIFAR10; .CIFAR100;} = .cifar
+{.MNIST; .FashionMNIST;} = .mnist
diff --git a/crates/erg_compiler/lib/external/torchvision.d/datasets.d/cifar.d.er b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/cifar.d.er
new file mode 100644
index 00000000..97e10002
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/cifar.d.er
@@ -0,0 +1,23 @@
+vision = pyimport "./vision"
+
+.CIFAR10: ClassType
+.CIFAR10 <: vision.VisionDataset
+.CIFAR10.
+    __call__: (
+        root: Str,
+        train := Bool,
+        download := Bool,
+        transform := GenericCallable,
+        target_transform := GenericCallable,
+    ) -> .CIFAR10
+
+.CIFAR100: ClassType
+.CIFAR100 <: .CIFAR10
+.CIFAR100.
+    __call__: (
+        root: Str,
+        train := Bool,
+        download := Bool,
+        transform := GenericCallable,
+        target_transform := GenericCallable,
+    ) -> .CIFAR100
diff --git a/crates/erg_compiler/lib/external/torchvision.d/datasets.d/mnist.d.er b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/mnist.d.er
new file mode 100644
index 00000000..1f75d71d
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/mnist.d.er
@@ -0,0 +1,23 @@
+vision = pyimport "./vision"
+
+.MNIST: ClassType
+.MNIST <: vision.VisionDataset
+.MNIST.
+    __call__: (
+        root: Str,
+        train := Bool,
+        download := Bool,
+        transform := GenericCallable,
+        target_transform := GenericCallable,
+    ) -> .MNIST
+
+.FashionMNIST: ClassType
+.FashionMNIST <: .MNIST
+.FashionMNIST.
+    __call__: (
+        root: Str,
+        train := Bool,
+        download := Bool,
+        transform := GenericCallable,
+        target_transform := GenericCallable,
+    ) -> .FashionMNIST
diff --git a/crates/erg_compiler/lib/external/torchvision.d/datasets.d/utils.d.er b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/utils.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/torchvision.d/datasets.d/vision.d.er b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/vision.d.er
new file mode 100644
index 00000000..d1e4e76a
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/datasets.d/vision.d.er
@@ -0,0 +1,15 @@
+dataset = pyimport "torch/utils/data/dataset"
+{Tensor!;} = pyimport "torch"
+
+.VisionDataset: ClassType
+.VisionDataset <: dataset.Dataset
+.VisionDataset|<: Indexable(Nat, (Tensor!(Float, _), Tensor!(Float, _)))|.
+    __getitem__: (index: Nat) -> (Tensor!(Float, _), Tensor!(Float, _))
+.VisionDataset.
+    __call__: (
+        root: Str,
+        train := Bool,
+        download := Bool,
+        transform := GenericCallable,
+        target_transform := GenericCallable,
+    ) -> .VisionDataset
diff --git a/crates/erg_compiler/lib/external/torchvision.d/models.d/__init__.d.er b/crates/erg_compiler/lib/external/torchvision.d/models.d/__init__.d.er
new file mode 100644
index 00000000..2260d412
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/models.d/__init__.d.er
@@ -0,0 +1,3 @@
+.resnet = pyimport "./resnet"
+
+{.ResNet; .resnet18;} = .resnet
diff --git a/crates/erg_compiler/lib/external/torchvision.d/models.d/resnet.d.er b/crates/erg_compiler/lib/external/torchvision.d/models.d/resnet.d.er
new file mode 100644
index 00000000..344a51bf
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/models.d/resnet.d.er
@@ -0,0 +1,6 @@
+{.Module;} = pyimport "torch/nn"
+
+.ResNet: ClassType
+.ResNet <: .Module
+
+.resnet18: () -> .ResNet
diff --git a/crates/erg_compiler/lib/external/torchvision.d/package.er b/crates/erg_compiler/lib/external/torchvision.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/torchvision.d/transforms.d/__init__.d.er b/crates/erg_compiler/lib/external/torchvision.d/transforms.d/__init__.d.er
new file mode 100644
index 00000000..6c12772d
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/transforms.d/__init__.d.er
@@ -0,0 +1,11 @@
+{
+    .Compose;
+    .CenterCrop;
+    .GrayScale;
+    .Normalize;
+    .RandomCrop;
+    .RandomHorizontalFlip;
+    .RandomResizedCrop;
+    .Resize;
+    .ToTensor;
+} = pyimport "./transforms"
diff --git a/crates/erg_compiler/lib/external/torchvision.d/transforms.d/transforms.d.er b/crates/erg_compiler/lib/external/torchvision.d/transforms.d/transforms.d.er
new file mode 100644
index 00000000..d14edd62
--- /dev/null
+++ b/crates/erg_compiler/lib/external/torchvision.d/transforms.d/transforms.d.er
@@ -0,0 +1,69 @@
+Transform: ClassType
+
+.Compose: ClassType
+.Compose <: GenericCallable
+.Compose.
+    __call__: (transforms: [Transform; _]) -> .Compose
+
+.CenterCrop: ClassType
+.CenterCrop <: Transform
+.CenterCrop <: GenericCallable
+.CenterCrop.
+    __call__: (size: Nat or (Nat, Nat) or [Nat; 2]) -> .CenterCrop
+
+.GrayScale: ClassType
+.GrayScale <: Transform
+.GrayScale <: GenericCallable
+.GrayScale.
+    __call__: () -> .GrayScale
+
+.Normalize: ClassType
+.Normalize <: Transform
+.Normalize <: GenericCallable
+.Normalize.
+    __call__: (
+        mean: [Float; _],
+        std: [Float; _],
+        inplace := Bool,
+    ) -> .Normalize
+
+.RandomCrop: ClassType
+.RandomCrop <: Transform
+.RandomCrop <: GenericCallable
+.RandomCrop.
+    __call__: (
+        size: Nat or (Nat, Nat) or [Nat; 2],
+        padding := Nat or (Nat, Nat) or (Nat, Nat, Nat, Nat),
+        pad_if_needed:=Bool,
+        fill := Nat or (Nat, Nat, Nat),
+        padding_mode := Str,
+    ) -> .RandomCrop
+
+.RandomHorizontalFlip: ClassType
+.RandomHorizontalFlip <: Transform
+.RandomHorizontalFlip <: GenericCallable
+.RandomHorizontalFlip.
+    __call__: () -> .RandomHorizontalFlip
+
+.RandomResizedCrop: ClassType
+.RandomResizedCrop <: Transform
+.RandomResizedCrop <: GenericCallable
+.RandomResizedCrop.
+    __call__: (size: Nat or (Nat, Nat) or [Nat; 2]) -> .RandomResizedCrop
+
+.Resize: ClassType
+.Resize <: Transform
+.Resize <: GenericCallable
+.Resize.
+    __call__: (
+        size: Nat or (Nat, Nat) or [Nat; 2],
+        interpolation := Str,
+        max_size := Nat,
+        antialias := Bool,
+    ) -> .Resize
+
+.ToTensor: ClassType
+.ToTensor <: Transform
+.ToTensor <: GenericCallable
+.ToTensor.
+    __call__: () -> .ToTensor
diff --git a/crates/erg_compiler/lib/external/tqdm.d/__init__.d.er b/crates/erg_compiler/lib/external/tqdm.d/__init__.d.er
new file mode 100644
index 00000000..b0d81d37
--- /dev/null
+++ b/crates/erg_compiler/lib/external/tqdm.d/__init__.d.er
@@ -0,0 +1,31 @@
+.Tqdm! = 'tqdm': (T: Type) -> ClassType
+.Tqdm!(T) <: Iterable T
+
+.tqdm: |T|(
+    iterable: Iterable(T),
+    desc := Str,
+    total := Int or Float,
+    leave := Bool,
+    file := File!,
+    ncols := Int,
+    mininterval := Float,
+    maxinterval := Float,
+    miniters := Int or Float,
+    ascii := Bool or Str,
+    disable := Bool,
+    unit := Str,
+    unit_scale := Bool or Int or Float,
+    dynamic_ncols := Bool,
+    smoothing := Float,
+    bar_format := Str,
+    initial := Int or Float,
+    position := Int,
+    postfix := {Str: Obj},
+    unit_divisor := Float,
+    write_bytes := Bool,
+    lock_args := [Obj; _],
+    nrows := Int,
+    colour := Str,
+    delay := Float,
+    gui := Bool,
+) -> .Tqdm!(T)
diff --git a/crates/erg_compiler/lib/external/tqdm.d/package.er b/crates/erg_compiler/lib/external/tqdm.d/package.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/urllib3.d/__init__.d.er b/crates/erg_compiler/lib/external/urllib3.d/__init__.d.er
new file mode 100644
index 00000000..e69de29b
diff --git a/crates/erg_compiler/lib/external/urllib3.d/package.er b/crates/erg_compiler/lib/external/urllib3.d/package.er
new file mode 100644
index 00000000..e69de29b