fact: Hypothesis (or: preorder r) (sr: substrate r = I) (fgE:fgraph E) (dE: domain E = I) (fgf: fgraph f) (df: domain f = r) (function_f: forall p, inc p r -> function_prop (Vg f p) (Vg E (P p)) (Vg E (Q p))) (compose_f: forall i j k, gle r i j -> gle r j k -> Vg f (J j k) \co Vg f (J i j) = Vg f (J i k)) (identity_f: forall i, inc i I -> Vg f (J i i) = identity (Vg E i)).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)