ext v w
case mp
V : Type u_1
G G' : Digraph V
h : G ≤ G'
⊢ G = deleteEdges G' (edgeSet G' \ edgeSet G)
case mp.Adj.h.h.a
V : Type u_1
G G' : Digraph V
h : G ≤ G'
v w : V
⊢ G.Adj v w ↔ (deleteEdges G' (edgeSet G' \ edgeSet G)).Adj v w