giles f5ab66e1a3 mk: foldl-o — relational left fold ...

Complement to foldr-o. The combiner relation has signature
(acc head new-acc) — accumulator first.

Examples:
  (foldl-o pluso-i (list 1 2 3 4 5) 0 q)  -> (15)
  (foldl-o *o-i    (list 1 2 3 4)   1 q)  -> (24)
  (foldl-o (fn (acc x r) (conso x acc r))  ; flipped conso
           (list 1 2 3 4) (list) q)        -> ((4 3 2 1))   ; reverse

5 new tests, 510/510 cumulative.

2026-05-08 12:23:40 +00:00

681 B

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