Module order 

Standard order of terms (ISO 8.4.2), ported from patch-prolog v1’s term_compare.

Order: Var < Number < Atom < Compound

• vars among themselves by heap-cell index (v1: VarId)
• numbers by value; Float < Integer when numerically equal; NaN last
• atoms alphabetically by name
• compounds by arity, then functor name, then args left-to-right

A LST cell IS the compound '.'(Head, Tail) — arity 2, functor “.”. We treat it as such so a LST and a STR with functor “.” / arity 2 compare structurally equal, exactly as v1 (which has a distinct Term::List but compares it against Compound('.', [h, t]) as equal — see the List-vs-Compound arms in v1 term_compare).

Functions

compare_terms

Total standard order over two heap words (after dereferencing).