You are correct; I seemed to remember there was a catch but was too lazy to check, sorry. This isn’t a precedence parser, that was 18b, while this one solves 18

You are correct; I seemed to remember there was a catch but was too lazy to check, sorry. This isn’t a precedence parser, that was 18b, while this one solves 18a, which was just to resolve parentheses correctly and disregard precedence. (Original comment fixed.)