Theorem: Digraph.Walk.concat_ne_nil (GraphProjects/DigraphConnectivity.lean)

State before:
V : Type u
V' : Type v
V'' : Type w
G : Digraph V
G' : Digraph V'
G'' : Digraph V''
u v : V
p : Walk G u v
h : G.Adj v u
⊢ concat p h ≠ nil
Tactic:
cases p <;> simp [concat]
State after:
no goals