Function rewrite_unary_bang_to_bnot 

pub(super) fn rewrite_unary_bang_to_bnot(s: &str) -> String

Rewrite unary !x to bnot(x). evalexpr 13 type-checks the ! operator as Boolean → Boolean; MD2 EEL2 treats it as numeric NOT (returns 1.0 if x == 0.0, else 0.0) — same semantics as bnot.