fact: Definition preim (U : pcm) V (D : rel U) (f : @morphism U V D) (R : rel V) of phantom (U -> V) f : rel U := fun x y => D x y && R (f x) (f y).
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(eqtype fintype) pcm(options axioms prelude) pcm(pcm)