diff --git a/compiler/erg_compiler/context/initialize/mod.rs b/compiler/erg_compiler/context/initialize/mod.rs
index d553fb3b..4f9cb507 100644
--- a/compiler/erg_compiler/context/initialize/mod.rs
+++ b/compiler/erg_compiler/context/initialize/mod.rs
@@ -2173,7 +2173,8 @@ impl Context {
         let T = mono_q("T", instanceof(Type));
         let I = mono_q("I", subtypeof(poly("In", vec![ty_tp(T.clone())])));
         let op_t = bin_op(I, T, Bool).quantify();
-        self.register_builtin_impl("__in__", op_t, Const, Private);
+        self.register_builtin_impl("__in__", op_t.clone(), Const, Private);
+        self.register_builtin_impl("__notin__", op_t, Const, Private);
         /* unary */
         // TODO: Boolの+/-は警告を出したい
         let M = mono_q("M", subtypeof(mono("Mutizable")));
diff --git a/compiler/erg_compiler/error.rs b/compiler/erg_compiler/error.rs
index be1857e4..818d228d 100644
--- a/compiler/erg_compiler/error.rs
+++ b/compiler/erg_compiler/error.rs
@@ -39,6 +39,7 @@ pub fn binop_to_dname(op: &str) -> &str {
         "//" => "__floordiv__",
         "**" => "__pow__",
         "%" => "__mod__",
+        "@" => "__matmul__",
         ".." => "__rng__",
         "<.." => "__lorng__",
         "..<" => "__rorng__",
@@ -47,6 +48,7 @@ pub fn binop_to_dname(op: &str) -> &str {
         "||" | "or" => "__or__",
         "^^" => "__xor__",
         "in" => "__in__",
+        "notin" => "__notin__", // NOTE: this doesn't exist in Python
         "contains" => "__contains__",
         "subof" => "__subof__",
         "supof" => "__supof__",
@@ -82,6 +84,7 @@ pub fn readable_name(name: &str) -> &str {
         "__floordiv__" => "`//`",
         "__pow__" => "`**`",
         "__mod__" => "`%`",
+        "__matmul__" => "`@`",
         "__rng__" => "`..`",
         "__lorng__" => "`<..`",
         "__rorng__" => "`..<`",
@@ -89,6 +92,7 @@ pub fn readable_name(name: &str) -> &str {
         "__and__" => "`and`",
         "__or__" => "`or`",
         "__in__" => "`in`",
+        "__notin__" => "`notin`",
         "__contains__" => "`contains`",
         "__subof__" => "`subof`",
         "__supof__" => "`supof`",