Theorem: Digraph.Walk.length_eq_zero_iff (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
p : Walk G u u
⊢ length p = 0 ↔ p = nil
Tactic:
cases p <;> simp
State after:
no goals