diff --git a/liblangutil/Token.h b/liblangutil/Token.h
index 871e67772..1072f6d6b 100644
--- a/liblangutil/Token.h
+++ b/liblangutil/Token.h
@@ -349,7 +349,7 @@ namespace TokenTraits
 	{
 		return tok == Token::Assembly || tok == Token::Contract || tok == Token::External || tok == Token::Fallback ||
 			tok == Token::Pragma || tok == Token::Import || tok == Token::As || tok == Token::Function || tok == Token::Let ||
-			tok == Token::Return || tok == Token::Type || (tok > Token::NonExperimentalEnd && tok < Token::ExperimentalEnd);
+			tok == Token::Return || tok == Token::Type || tok == Token::Bool || (tok > Token::NonExperimentalEnd && tok < Token::ExperimentalEnd);
 	}
 	constexpr bool isExperimentalSolidityOnlyKeyword(Token tok)
 	{
diff --git a/libsolidity/analysis/experimental/TypeInference.cpp b/libsolidity/analysis/experimental/TypeInference.cpp
index 6dc8cc973..f1fd5e93a 100644
--- a/libsolidity/analysis/experimental/TypeInference.cpp
+++ b/libsolidity/analysis/experimental/TypeInference.cpp
@@ -48,6 +48,7 @@ m_typeSystem(_analysis.typeSystem())
 	m_wordType = m_typeSystem.type(BuiltinType::Word, {});
 	m_integerType = m_typeSystem.type(BuiltinType::Integer, {});
 	m_unitType = m_typeSystem.type(BuiltinType::Unit, {});
+	m_boolType = m_typeSystem.type(BuiltinType::Bool, {});
 	m_env = &m_typeSystem.env();
 }
 
@@ -272,6 +273,9 @@ bool TypeInference::visit(ElementaryTypeNameExpression const& _expression)
 	case Token::Unit:
 		expressionAnnotation.type = helper.kindType(m_unitType);
 		break;
+	case Token::Bool:
+		expressionAnnotation.type = helper.kindType(m_boolType);
+		break;
 	case Token::Pair:
 	{
 		auto leftType = m_typeSystem.freshTypeVariable(false, {});
@@ -1055,7 +1059,6 @@ optional<rational> rationalValue(Literal const& _literal)
 bool TypeInference::visit(Literal const& _literal)
 {
 	auto& literalAnnotation = annotation(_literal);
-	literalAnnotation.type = m_typeSystem.freshTypeVariable(false, {});
 	if (_literal.token() != Token::Number)
 	{
 		 m_errorReporter.typeError(0000_error, _literal.location(), "Only number literals are supported.");
@@ -1072,5 +1075,6 @@ bool TypeInference::visit(Literal const& _literal)
 		 m_errorReporter.typeError(0000_error, _literal.location(), "Only integers are supported.");
 		 return false;
 	}
+	literalAnnotation.type = m_typeSystem.freshTypeVariable(false, Sort{{TypeClass{BuiltinClass::Integer}}});
 	return false;
 }
diff --git a/libsolidity/analysis/experimental/TypeInference.h b/libsolidity/analysis/experimental/TypeInference.h
index 1841b131a..afbea93e9 100644
--- a/libsolidity/analysis/experimental/TypeInference.h
+++ b/libsolidity/analysis/experimental/TypeInference.h
@@ -94,6 +94,7 @@ private:
 	Type m_wordType;
 	Type m_integerType;
 	Type m_unitType;
+	Type m_boolType;
 	std::optional<Type> m_currentFunctionType;
 
 	Annotation& annotation(ASTNode const& _node);
diff --git a/libsolidity/analysis/experimental/TypeRegistration.cpp b/libsolidity/analysis/experimental/TypeRegistration.cpp
index 05d93a85d..4d95a8d27 100644
--- a/libsolidity/analysis/experimental/TypeRegistration.cpp
+++ b/libsolidity/analysis/experimental/TypeRegistration.cpp
@@ -41,7 +41,8 @@ m_typeSystem(_analysis.typeSystem())
 		{BuiltinType::Unit, "unit", 0},
 		{BuiltinType::Pair, "pair", 2},
 		{BuiltinType::Word, "word", 0},
-		{BuiltinType::Integer, "integer", 0}
+		{BuiltinType::Integer, "integer", 0},
+ 		{BuiltinType::Bool, "bool", 0}
 	})
 		m_typeSystem.declareTypeConstructor(type, name, arity);
 
@@ -80,6 +81,23 @@ m_typeSystem(_analysis.typeSystem())
 
 	defineBinaryMonoidalOperator(BuiltinClass::Mul, Token::Mul, "mul");
 	defineBinaryMonoidalOperator(BuiltinClass::Add, Token::Add, "add");
+
+	auto defineBinaryCompareOperator = [&](BuiltinClass _class, Token _token, std::string _name) {
+		declareBuiltinClass(_class, [&](Type _typeVar) -> MemberList {
+			return {
+				{
+					_name,
+					helper.functionType(helper.tupleType({_typeVar, _typeVar}), TypeConstant{BuiltinType::Bool, {}})
+				}
+			};
+		});
+		annotation().operators[_token] = std::make_tuple(TypeClass{_class}, _name);
+	};
+	defineBinaryCompareOperator(BuiltinClass::Equal, Token::Equal, "eq");
+	defineBinaryCompareOperator(BuiltinClass::Less, Token::LessThan, "lt");
+	defineBinaryCompareOperator(BuiltinClass::LessOrEqual, Token::LessThanOrEqual, "leq");
+	defineBinaryCompareOperator(BuiltinClass::Greater, Token::GreaterThan, "gt");
+	defineBinaryCompareOperator(BuiltinClass::GreaterOrEqual, Token::GreaterThanOrEqual, "geq");
 }
 
 bool TypeRegistration::analyze(SourceUnit const& _sourceUnit)
diff --git a/libsolidity/ast/experimental/Type.cpp b/libsolidity/ast/experimental/Type.cpp
index 2d0a7dd40..487b97bb5 100644
--- a/libsolidity/ast/experimental/Type.cpp
+++ b/libsolidity/ast/experimental/Type.cpp
@@ -77,6 +77,16 @@ string TypeClass::toString() const
 				return "*";
 			case BuiltinClass::Add:
 				return "+";
+			case BuiltinClass::Equal:
+				return "==";
+			case BuiltinClass::Less:
+				return "<";
+			case BuiltinClass::LessOrEqual:
+				return "<=";
+			case BuiltinClass::Greater:
+				return ">";
+			case BuiltinClass::GreaterOrEqual:
+				return ">=";
 			}
 			solAssert(false);
 		},
diff --git a/libsolidity/ast/experimental/Type.h b/libsolidity/ast/experimental/Type.h
index f409efb60..4fb7e6c8d 100644
--- a/libsolidity/ast/experimental/Type.h
+++ b/libsolidity/ast/experimental/Type.h
@@ -47,6 +47,7 @@ enum class BuiltinType
 	Unit,
 	Pair,
 	Word,
+	Bool,
 	Integer
 };
 
@@ -75,7 +76,12 @@ enum class BuiltinClass
 	Constraint,
 	Integer,
 	Mul,
-	Add
+	Add,
+	Equal,
+	Less,
+	LessOrEqual,
+	Greater,
+	GreaterOrEqual
 };
 
 struct TypeClass
diff --git a/libsolidity/ast/experimental/TypeSystem.cpp b/libsolidity/ast/experimental/TypeSystem.cpp
index ffa01fa3c..751aa9864 100644
--- a/libsolidity/ast/experimental/TypeSystem.cpp
+++ b/libsolidity/ast/experimental/TypeSystem.cpp
@@ -85,6 +85,9 @@ std::string TypeEnvironment::canonicalTypeName(Type _type) const
 					case BuiltinType::Word:
 						stream << "word";
 						break;
+					case BuiltinType::Bool:
+						stream << "bool";
+						break;
 					case BuiltinType::Integer:
 						stream << "integer";
 						break;
diff --git a/libsolidity/ast/experimental/TypeSystemHelper.cpp b/libsolidity/ast/experimental/TypeSystemHelper.cpp
index 44679e08e..cf0a92bd1 100644
--- a/libsolidity/ast/experimental/TypeSystemHelper.cpp
+++ b/libsolidity/ast/experimental/TypeSystemHelper.cpp
@@ -62,6 +62,8 @@ std::optional<TypeConstructor> experimental::typeConstructorFromToken(langutil::
 		return BuiltinType::Word;
 	case Token::Integer:
 		return BuiltinType::Integer;
+	case Token::Bool:
+		return BuiltinType::Bool;
 	default:
 		return nullopt;
 	}
@@ -77,6 +79,16 @@ std::optional<TypeClass> experimental::typeClassFromToken(langutil::Token _token
 		return TypeClass{BuiltinClass::Mul};
 	case Token::Add:
 		return TypeClass{BuiltinClass::Add};
+	case Token::Equal:
+		return TypeClass{BuiltinClass::Equal};
+	case Token::LessThan:
+		return TypeClass{BuiltinClass::Less};
+	case Token::LessThanOrEqual:
+		return TypeClass{BuiltinClass::LessOrEqual};
+	case Token::GreaterThan:
+		return TypeClass{BuiltinClass::Greater};
+	case Token::GreaterThanOrEqual:
+		return TypeClass{BuiltinClass::GreaterOrEqual};
 	default:
 		return nullopt;
 	}
diff --git a/test/libsolidity/semanticTests/experimental/stub.sol b/test/libsolidity/semanticTests/experimental/stub.sol
index 16bc55137..7cbe94149 100644
--- a/test/libsolidity/semanticTests/experimental/stub.sol
+++ b/test/libsolidity/semanticTests/experimental/stub.sol
@@ -32,15 +32,28 @@ instantiation word: * {
     }
 }
 
+instantiation word: integer {
+    function fromInteger(x:integer) -> y:word {
+    }
+}
+
+instantiation word: == {
+    function eq(x, y) -> z:bool {
+        assembly {
+            x := eq(x, y)
+        }
+    }
+}
+
 contract C {
 	fallback() external {
 		let x : word;
 		assembly {
 			x := 0x10
 		}
-        let w: uint256 = uint256.abs(x);
+        let w = uint256.abs(x);
         w = w * w + w;
-		let y : word = 2;
+		let y : word;
         assembly { y := 2 }
         y = uint256.rep(w) * y;
 		assembly {