run expr "let\n    a = 4 * [7 + 1 - 1)\n in a * a" :: IO Expr
run expr "let\n    a = 4 * (7 + 1 - 1\n in a * a" :: IO Expr
run expr "let\n    a = 4 * (7 + 1 - 1)\n a * a" :: IO Expr
run expr "\n    a = 4 * (7 + 1 - 1)\n in a * a" :: IO Expr
run expr "let\n    a = 4 * (7 + - 1)\n in a * a" :: IO Expr
run expr "let\n    a = 4  (7 + 1 - 1)\n in a * a" :: IO Expr