infer's :invoke case was ~120 lines of cond arms hand-coding eight call
patterns, all destructured positionally with (nth r 0)/(nth r 1) on the
[type node'] tuples infer returns. Split each pattern into a named helper
(infer-pred-fold/-kw-lookup/-get-lookup/-reduce-hof/-seq-hof/-conj-into/-call)
behind an infer-invoke dispatcher that keeps the cond guards verbatim, and add
ty/nd accessors for the tuple so a silent transposition can't hide.
The accessors are applied only to genuine infer results (the new helpers and
infer-fn-seeded); the :map/:let/:loop arms interleave non-infer pairs
(binding tuples, accumulator pairs) with infer results, so those keep nth.
Pure restructuring — the guards, order, and bodies are unchanged; seed
re-minted to the byte-fixpoint, gate green, 0 new corpus divergences.
54c3c6dd2b