Theorem: Digraph.Walk.copy_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 u' : V
hu : u = u'
⊢ Walk.copy nil hu hu = nil
Tactic:
subst_vars
State after:
V : Type u
V' : Type v
V'' : Type w
G : Digraph V
G' : Digraph V'
G'' : Digraph V''
u' : V
⊢ Walk.copy nil (_ : u' = u') (_ : u' = u') = nil

State before:
V : Type u
V' : Type v
V'' : Type w
G : Digraph V
G' : Digraph V'
G'' : Digraph V''
u' : V
⊢ Walk.copy nil (_ : u' = u') (_ : u' = u') = nil
Tactic:
rfl
State after:
no goals