diff --git a/midas/checker/checker.py b/midas/checker/checker.py
index 4ebedd5..cec5c80 100644
--- a/midas/checker/checker.py
+++ b/midas/checker/checker.py
@@ -8,7 +8,7 @@ import midas.ast.python as p
 from midas.ast.location import Location
 from midas.checker.diagnostic import Diagnostic, DiagnosticType
 from midas.checker.environment import Environment
-from midas.checker.operators import OPERATOR_METHODS
+from midas.checker.operators import COMPARATOR_METHODS, OPERATOR_METHODS
 from midas.checker.types import Function, Type, UnitType, UnknownType
 from midas.lexer.midas import MidasLexer
 from midas.lexer.token import Token
@@ -294,7 +294,23 @@ class Checker(
             return UnknownType()
         return result
 
-    def visit_compare_expr(self, expr: p.CompareExpr) -> Type: ...
+    def visit_compare_expr(self, expr: p.CompareExpr) -> Type:
+        method: Optional[str] = COMPARATOR_METHODS.get(expr.operator.__class__)
+        if method is None:
+            self.logger.warning(f"Unsupported operator {expr.operator}")
+            self.warning(expr.location, f"Unsupported operator {expr.operator}")
+            return UnknownType()
+        left: Type = self.evaluate(expr.left)
+        right: Type = self.evaluate(expr.right)
+
+        result: Optional[Type] = self.ctx.get_operation_result(left, method, right)
+        if result is None:
+            self.error(
+                expr.location,
+                f"Undefined operation {method} between {left} and {right}",
+            )
+            return UnknownType()
+        return result
 
     def visit_unary_expr(self, expr: p.UnaryExpr) -> Type: ...
 
diff --git a/midas/resolver/builtin.py b/midas/resolver/builtin.py
index 0ceae90..6a00b14 100644
--- a/midas/resolver/builtin.py
+++ b/midas/resolver/builtin.py
@@ -2,12 +2,20 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
-from midas.checker.types import BaseType, Type
+from midas.checker.types import BaseType, Type, UnitType
 
 if TYPE_CHECKING:
     from midas.resolver.midas import MidasResolver
 
 
+def op(ctx: MidasResolver, t1: Type, operator: str, t2: Type, t3: Type):
+    ctx.define_operation(
+        left=t1,
+        operator=operator,
+        right=t2,
+        result=t3,
+    )
+
 def basic_op(ctx: MidasResolver, type: Type, op: str):
     ctx.define_operation(
         left=type,
@@ -19,21 +27,45 @@ def basic_op(ctx: MidasResolver, type: Type, op: str):
 
 def define_builtins(ctx: MidasResolver):
     """Define builtin types and operations"""
+    unit = ctx.define_type("None", UnitType())
     bool = ctx.define_type("bool", BaseType(name="bool"))
     int = ctx.define_type("int", BaseType(name="int"))
     float = ctx.define_type("float", BaseType(name="float"))
     str = ctx.define_type("str", BaseType(name="str"))
 
-    basic_op(ctx, int, "__add__")
-    basic_op(ctx, int, "__sub__")
-    basic_op(ctx, int, "__mul__")
-    basic_op(ctx, int, "__pow__")
-    basic_op(ctx, int, "__mod__")
-    basic_op(ctx, int, "__and__")
-    basic_op(ctx, int, "__or__")
-    basic_op(ctx, int, "__xor__")
-    basic_op(ctx, float, "__add__")
-    basic_op(ctx, float, "__sub__")
-    basic_op(ctx, float, "__mul__")
-    basic_op(ctx, float, "__truediv__")
-    basic_op(ctx, str, "__add__")
+    basic_op(ctx, int, "__add__")  # int + int = int
+    basic_op(ctx, int, "__sub__")  # int - int = int
+    basic_op(ctx, int, "__mul__")  # int * int = int
+    basic_op(ctx, int, "__pow__")  # int ** int = int
+    basic_op(ctx, int, "__mod__")  # int % int = int
+    basic_op(ctx, int, "__and__")  # int & int = int
+    basic_op(ctx, int, "__or__")  # int | int = int
+    basic_op(ctx, int, "__xor__")  # int ^ int = int
+    op(ctx, int, "__lt__", int, bool)  # int < int = bool
+    op(ctx, int, "__gt__", int, bool)  # int > int = bool
+    op(ctx, int, "__le__", int, bool)  # int <= int = bool
+    op(ctx, int, "__ge__", int, bool)  # int >= int = bool
+    op(ctx, int, "__eq__", int, bool)  # int == int = bool
+    basic_op(ctx, float, "__add__")  # float + float = float
+    basic_op(ctx, float, "__sub__")  # float - float = float
+    basic_op(ctx, float, "__mul__")  # float * float = float
+    basic_op(ctx, float, "__truediv__")  # float / float = float
+    op(ctx, float, "__lt__", float, bool)  # float < float = bool
+    op(ctx, float, "__gt__", float, bool)  # float > float = bool
+    op(ctx, float, "__le__", float, bool)  # float <= float = bool
+    op(ctx, float, "__ge__", float, bool)  # float >= float = bool
+    op(ctx, float, "__eq__", float, bool)  # float == float = bool
+    basic_op(ctx, str, "__add__")  # str + str = str
+    op(ctx, str, "__eq__", str, bool)  # str == str = bool
+
+    op(ctx, int, "__lt__", float, bool)  # int < float = bool
+    op(ctx, int, "__gt__", float, bool)  # int > float = bool
+    op(ctx, int, "__le__", float, bool)  # int <= float = bool
+    op(ctx, int, "__ge__", float, bool)  # int >= float = bool
+    op(ctx, int, "__eq__", float, bool)  # int == float = bool
+
+    op(ctx, float, "__lt__", int, bool)  # float < int = bool
+    op(ctx, float, "__gt__", int, bool)  # float > int = bool
+    op(ctx, float, "__le__", int, bool)  # float <= int = bool
+    op(ctx, float, "__ge__", int, bool)  # float >= int = bool
+    op(ctx, float, "__eq__", int, bool)  # float == int = bool
\ No newline at end of file