I see what you mean: Math uses 2D notations with fixed positions. The space around an operator can be subdivided into nine sections (top, bottom, left, right, corners). That yields up to nine positions for operands. Fixed positions means, effectively, no precedence parsing, just like what S-exps do in one dimension. The operands themselves use spatial subdivision likewise. E.g:
That being said, a lot of mathematical notation is pretty close to lisp syntax, basically anything that works like sigma.