Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/prelude/Prelude/Eq_3.hs
module Prelude(Eq(..)) where instance (Eq a,Eq b, Eq c) => Eq (a,b,c) where (a,b,c) == (a',b',c') = a == a' && b == b' && c == c'