ground_2 released and permanently renamed as ground

[helm.git] / matita / matita / contribs / lambdadelta / ground / etc / lib / logic.etc

lemma eq_repl4: ∀A,B,C,D.∀R:relation4 A B C D.
∀x1,x2:A.∀y1,y2:B. ∀z1,z2:C. ∀w1,w2:D. x1=x2 → y1=y2 → z1=z2 → w1=w2 → R x2 y2 z2 w2 → R x1 y1 z1 w1.
// qed-.