Constant NUMERIC_HASH_P 

pub const NUMERIC_HASH_P: u64 = _; // 2_305_843_009_213_693_951u64

The Mersenne prime 2^61 − 1: the modulus of the UNIFIED numeric hash. Every numeric type hashes to its mathematical value mod P, so values that compare equal across types (1 == 1.0 == 1/1) hash equal — the hash/ equality coherence law that lets mixed-type map keys unify.