You need infix, but that's not enough. Mathematics isn't written with infix operators alone. Mathematics is written in a fancy 2d notation with all kinds of op

You need infix, but that's not enough. Mathematics isn't written with infix operators alone. Mathematics is written in a fancy 2d notation with all kinds of operator types: infix, prefix, postfix, around-fix, sub-fix, super-fix. If you look at actual software for maths - several famous ones were written in Lisp like Macsyma, Reduce and Axiom - they provide more than infix.