BinOpApp Plus (Let "x" (BinOpApp Plus (LitInt 1) (LitInt 2)) (Let "y" (BinOpApp Times (Var "x") (Var "x")) (Let "x" (BinOpApp Plus (Var "y") (BinOpApp Plus (Var "x") (LitInt 42))) (BinOpApp Times (Var "x") (Var "x"))))) (LitInt 2)