diff --git a/core/ast/midas.py b/core/ast/midas.py
index 281c8a4..f4280fb 100644
--- a/core/ast/midas.py
+++ b/core/ast/midas.py
@@ -47,7 +47,7 @@ class Stmt(ABC):
 class SimpleTypeStmt(Stmt):
     name: Token
     template: Optional[TemplateExpr]
-    base: SimpleTypeExpr
+    base: TypeExpr
     constraint: Optional[Expr]
 
     def accept(self, visitor: Stmt.Visitor[T]) -> T:
@@ -68,6 +68,7 @@ class ComplexTypeStmt(Stmt):
 class PropertyStmt(Stmt):
     name: Token
     type: TypeExpr
+    constraint: Optional[Expr]
 
     def accept(self, visitor: Stmt.Visitor[T]) -> T:
         return visitor.visit_property_stmt(self)
@@ -117,12 +118,24 @@ class Expr(ABC):
         @abstractmethod
         def visit_simple_type_expr(self, expr: SimpleTypeExpr) -> T: ...
 
+        @abstractmethod
+        def visit_logical_expr(self, expr: LogicalExpr) -> T: ...
+
         @abstractmethod
         def visit_binary_expr(self, expr: BinaryExpr) -> T: ...
 
         @abstractmethod
         def visit_unary_expr(self, expr: UnaryExpr) -> T: ...
 
+        @abstractmethod
+        def visit_get_expr(self, expr: GetExpr) -> T: ...
+
+        @abstractmethod
+        def visit_variable_expr(self, expr: VariableExpr) -> T: ...
+
+        @abstractmethod
+        def visit_grouping_expr(self, expr: GroupingExpr) -> T: ...
+
         @abstractmethod
         def visit_literal_expr(self, expr: LiteralExpr) -> T: ...
 
@@ -145,6 +158,16 @@ class SimpleTypeExpr(Expr):
         return visitor.visit_simple_type_expr(self)
 
 
+@dataclass(frozen=True)
+class LogicalExpr(Expr):
+    left: Expr
+    operator: Token
+    right: Expr
+
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
+        return visitor.visit_logical_expr(self)
+
+
 @dataclass(frozen=True)
 class BinaryExpr(Expr):
     left: Expr
@@ -164,6 +187,31 @@ class UnaryExpr(Expr):
         return visitor.visit_unary_expr(self)
 
 
+@dataclass(frozen=True)
+class GetExpr(Expr):
+    expr: Expr
+    name: Token
+
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
+        return visitor.visit_get_expr(self)
+
+
+@dataclass(frozen=True)
+class VariableExpr(Expr):
+    name: Token
+
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
+        return visitor.visit_variable_expr(self)
+
+
+@dataclass(frozen=True)
+class GroupingExpr(Expr):
+    expr: Expr
+
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
+        return visitor.visit_grouping_expr(self)
+
+
 @dataclass(frozen=True)
 class LiteralExpr(Expr):
     value: Any
@@ -174,7 +222,7 @@ class LiteralExpr(Expr):
 
 @dataclass(frozen=True)
 class WildcardExpr(Expr):
-    pass
+    token: Token
 
     def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_wildcard_expr(self)
diff --git a/gen/ast.py b/gen/ast.py
index 500a76d..6fca631 100644
--- a/gen/ast.py
+++ b/gen/ast.py
@@ -1,13 +1,18 @@
 class SimpleTypeStmt:
     name: Token
     template: Optional[TemplateExpr]
-    base: SimpleTypeExpr
+    base: TypeExpr
     constraint: Optional[Expr]
 
 class SimpleTypeExpr:
     name: Token
     optional: bool
 
+class LogicalExpr:
+    left: Expr
+    operator: Token
+    right: Expr
+
 class BinaryExpr:
     left: Expr
     operator: Token
@@ -17,11 +22,21 @@ class UnaryExpr:
     operator: Token
     right: Expr
 
+class GetExpr:
+    expr: Expr
+    name: Token
+
+class VariableExpr:
+    name: Token
+
+class GroupingExpr:
+    expr: Expr
+
 class LiteralExpr:
     value: Any
 
 class WildcardExpr:
-    pass
+    token: Token
 
 class TemplateExpr:
     type: TypeExpr
@@ -39,6 +54,7 @@ class ComplexTypeStmt:
 class PropertyStmt:
     name: Token
     type: TypeExpr
+    constraint: Optional[Expr]
 
 class ExtendStmt:
     type: TypeExpr
diff --git a/gen/gen.py b/gen/gen.py
index 18aabba..47cb827 100644
--- a/gen/gen.py
+++ b/gen/gen.py
@@ -77,7 +77,7 @@ def make_visitor_method(cls: str, param: str):
     )
     return method.strip("\n")
 
-def make_class(name: str, cls: str, base: str, param: str):
+def make_class(name: str, cls: str, base: str):
     body: str = cls.split("\n", 1)[1]
     func_name: str = snake_case(name)
     cls_def: str = CLASS_TEMPLATE.format(
@@ -101,10 +101,10 @@ def generate(src: str):
         print(f"Processing {name}")
         if name.endswith("Stmt"):
             stmt_visitor_methods.append(make_visitor_method(name, "stmt"))
-            statements.append(make_class(name, cls, "Stmt", "stmt"))
+            statements.append(make_class(name, cls, "Stmt"))
         elif name.endswith("Expr"):
             expr_visitor_methods.append(make_visitor_method(name, "expr"))
-            expressions.append(make_class(name, cls, "Expr", "expr"))
+            expressions.append(make_class(name, cls, "Expr"))
 
     return TEMPLATE.format(
         header=HEADER,