-- Double-minus prefix-binop trap (ILO-P021).
-- The intuitive transcription of `-g*s - b*om` into prefix form is
-- - -*gl s *b om
-- but that parses as `-((g*s) - (b*om)) = -g*s + b*om` — the sign of the
-- second product gets flipped. The parser now rejects that shape outright
-- with ILO-P021 so the silent miscompile can't happen. Two safe forms:
-- Form 1: subtract the SUM of both products from zero. Cheapest.
-- = 0 - (g*s + b*om) = -g*s - b*om
damped-a gl:n s:n b:n om:n>n;- 0 +*gl s *b om
-- Form 2: bind each product, then subtract one from the negation of the
-- other (or any other unambiguous combination).
-- nbom = -b*om ; result = -g*s + nbom = -g*s - b*om
damped-b gl:n s:n b:n om:n>n;p=*gl s;q=*b om;- 0 +p q
-- run: damped-a 1 1 0.5 1
-- out: -1.5
-- run: damped-b 1 1 0.5 1
-- out: -1.5
-- run: damped-a 2 1 0.25 3
-- out: -2.75
-- run: damped-b 2 1 0.25 3
-- out: -2.75