+semVarDecl :: VarDecl -> Env VarDecl
+semVarDecl v = pure $ Right v
+//Right v
+//semVarDecl vd=:(VarDecl pos type ident expr) = case unify type expr of
+// Left e = Left e
+// //TODO ident in de environment
+// Right e = Right $ pure vd
+//
+//typeExpr :: Expr -> Env Type
+//typeExpr (IntExpr _ _) = Right $ pure IntType
+//typeExpr (CharExpr _ _) = Right $ pure CharType
+//typeExpr (BoolExpr _ _) = Right $ pure BoolType
+//typeExpr (Op1Expr p UnNegation expr) = undef//typeExpr expr
+//// >>= \exprtype->case exprtype of
+//// Right BoolType = Right $ pure BoolType
+//// t = Left $ UnifyError p BoolType exprtype
+//typeExpr (Op1Expr p UnMinus expr) = undef// typeExpr expr
+//// >>= \exprtype->case exprtype of
+//// IntType = Right $ pure IntType
+//// t = Left $ UnifyError p IntType exprtype
+//// typeExpr (Op2Expr Pos Expr Op2 Expr) = undef
+////typeExpr (FunExpr Pos FunCall
+////typeExpr (EmptyListExpr Pos
+////typeExpr (TupleExpr Pos (Expr, Expr)
+////typeExpr (VarExpr Pos VarDef) = undef
+////
+//class unify a :: Type a -> Env a
+//
+//instance unify Type where
+// unify IntType IntType = Right $ pure IntType
+// unify BoolType BoolType = Right $ pure BoolType
+// unify CharType CharType = Right $ pure CharType
+// unify _ _ = undef
+//
+//instance unify Expr where
+// unify type expr = case type of
+// _ ->> _ = Left $ ParseError (extrPos expr)
+// "Expression cannot be a higher order function. Yet..."
+// VoidType = Left $ ParseError (extrPos expr)
+// "Expression cannot be a Void type."
+// IdType _ = Left $ ParseError (extrPos expr)
+// "Expression cannot be an polymorf type."
+// TupleType (_, _) = undef
+// ListType _ = undef
+// IntType = undef
+// BoolType = undef
+// CharType = undef
+// VarType = undef
+//
+//extrPos :: Expr -> Pos
+//extrPos (VarExpr p _) = p
+//extrPos (Op2Expr p _ _ _) = p
+//extrPos (Op1Expr p _ _) = p
+//extrPos (IntExpr p _) = p
+//extrPos (CharExpr p _) = p
+//extrPos (BoolExpr p _) = p
+//extrPos (FunExpr p _) = p
+//extrPos (EmptyListExpr p) = p
+//extrPos (TupleExpr p _) = p