diff --git a/crates/erg_compiler/context/initialize/classes.rs b/crates/erg_compiler/context/initialize/classes.rs
index 69053817..1a93b5f3 100644
--- a/crates/erg_compiler/context/initialize/classes.rs
+++ b/crates/erg_compiler/context/initialize/classes.rs
@@ -204,7 +204,12 @@ impl Context {
             ValueObj::builtin_t(Float),
         );
         float.register_trait(Float, float_floordiv);
-        let mut float_pos = Self::builtin_methods(Some(mono(POS)), 1);
+        let mut float_pos = Self::builtin_methods(Some(mono(POS)), 2);
+        float_pos.register_builtin_const(
+            OUTPUT,
+            Visibility::BUILTIN_PUBLIC,
+            ValueObj::builtin_t(Float),
+        );
         float_pos.register_builtin_erg_impl(
             OP_POS,
             fn0_met(Float, Float),
@@ -212,7 +217,12 @@ impl Context {
             Visibility::BUILTIN_PUBLIC,
         );
         float.register_trait(Float, float_pos);
-        let mut float_neg = Self::builtin_methods(Some(mono(NEG)), 1);
+        let mut float_neg = Self::builtin_methods(Some(mono(NEG)), 2);
+        float_neg.register_builtin_const(
+            OUTPUT,
+            Visibility::BUILTIN_PUBLIC,
+            ValueObj::builtin_t(Float),
+        );
         float_neg.register_builtin_erg_impl(
             OP_NEG,
             fn0_met(Float, Float),
@@ -461,6 +471,11 @@ impl Context {
         );
         int.register_trait(Int, int_floordiv);
         let mut int_pos = Self::builtin_methods(Some(mono(POS)), 2);
+        int_pos.register_builtin_const(
+            OUTPUT,
+            Visibility::BUILTIN_PUBLIC,
+            ValueObj::builtin_t(Int),
+        );
         int_pos.register_builtin_erg_impl(
             OP_POS,
             fn0_met(Int, Int),
@@ -469,6 +484,11 @@ impl Context {
         );
         int.register_trait(Int, int_pos);
         let mut int_neg = Self::builtin_methods(Some(mono(NEG)), 2);
+        int_neg.register_builtin_const(
+            OUTPUT,
+            Visibility::BUILTIN_PUBLIC,
+            ValueObj::builtin_t(Int),
+        );
         int_neg.register_builtin_erg_impl(
             OP_NEG,
             fn0_met(Int, Int),
diff --git a/crates/erg_compiler/context/initialize/funcs.rs b/crates/erg_compiler/context/initialize/funcs.rs
index 86ebc8e8..f0d94a0a 100644
--- a/crates/erg_compiler/context/initialize/funcs.rs
+++ b/crates/erg_compiler/context/initialize/funcs.rs
@@ -564,9 +564,11 @@ impl Context {
         let M = mono_q(TY_M, subtypeof(mono(MUTIZABLE)));
         let op_t = func1(M.clone(), proj(M, MUTABLE_MUT_TYPE)).quantify();
         self.register_builtin_erg_impl(OP_MUTATE, op_t, Const, Visibility::BUILTIN_PRIVATE);
-        let N = mono_q(TY_N, subtypeof(mono(NUM)));
-        let op_t = func1(N.clone(), N).quantify();
-        self.register_builtin_erg_decl(OP_POS, op_t.clone(), Visibility::BUILTIN_PRIVATE);
+        let P = mono_q(TY_N, subtypeof(mono(POS)));
+        let op_t = func1(P.clone(), proj(P, OUTPUT)).quantify();
+        self.register_builtin_erg_decl(OP_POS, op_t, Visibility::BUILTIN_PRIVATE);
+        let N = mono_q(TY_N, subtypeof(mono(NEG)));
+        let op_t = func1(N.clone(), proj(N, OUTPUT)).quantify();
         self.register_builtin_erg_decl(OP_NEG, op_t, Visibility::BUILTIN_PRIVATE);
     }
 
diff --git a/crates/erg_compiler/lib/std/_erg_float.py b/crates/erg_compiler/lib/std/_erg_float.py
index 622374fa..d11a36c7 100644
--- a/crates/erg_compiler/lib/std/_erg_float.py
+++ b/crates/erg_compiler/lib/std/_erg_float.py
@@ -34,6 +34,10 @@ class Float(float):
         return then__(float.__pow__(self, other), Float)
     def __rpow__(self, other):
         return then__(float.__pow__(float(other), self), Float)
+    def __pos__(self):
+        return self
+    def __neg__(self):
+        return then__(float.__neg__(self), Float)
 
 class FloatMut(): # inherits Float
     value: Float
@@ -102,3 +106,7 @@ class FloatMut(): # inherits Float
             return FloatMut(self.value ** other)
         else:
             return FloatMut(self.value ** other.value)
+    def __pos__(self):
+        return self
+    def __neg__(self):
+        return FloatMut(-self.value)
diff --git a/crates/erg_compiler/lib/std/_erg_int.py b/crates/erg_compiler/lib/std/_erg_int.py
index 9999c11d..39284af5 100644
--- a/crates/erg_compiler/lib/std/_erg_int.py
+++ b/crates/erg_compiler/lib/std/_erg_int.py
@@ -37,6 +37,10 @@ class Int(int):
         return then__(int.__pow__(self, other), Int)
     def __rpow__(self, other):
         return then__(int.__pow__(other, self), Int)
+    def __pos__(self):
+        return self
+    def __neg__(self):
+        return then__(int.__neg__(self), Int)
 
 class IntMut(): # inherits Int
     value: Int
@@ -102,6 +106,10 @@ class IntMut(): # inherits Int
             return IntMut(self.value ** other)
         else:
             return IntMut(self.value ** other.value)
+    def __pos__(self):
+        return self
+    def __neg__(self):
+        return IntMut(-self.value)
     def inc(self, i=1):
         self.value = Int(self.value + i)
     def dec(self, i=1):
diff --git a/crates/erg_compiler/lib/std/_erg_nat.py b/crates/erg_compiler/lib/std/_erg_nat.py
index 90a64f97..2f633dc5 100644
--- a/crates/erg_compiler/lib/std/_erg_nat.py
+++ b/crates/erg_compiler/lib/std/_erg_nat.py
@@ -25,6 +25,8 @@ class Nat(Int):
         return then__(super().__add__(other), Nat)
     def __mul__(self, other):
         return then__(super().__mul__(other), Nat)
+    def __pos__(self):
+        return self
 
 class NatMut(IntMut): # and Nat
     value: Nat
@@ -90,6 +92,8 @@ class NatMut(IntMut): # and Nat
             return NatMut(self.value ** other)
         else:
             return NatMut(self.value ** other.value)
+    def __pos__(self):
+        return self
     def try_new(i): # -> Result[Nat]
         if i >= 0:
             return NatMut(i)