Theorem: Digraph.Walk.length_copy (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 u' v' : V
p : Walk G u v
hu : u = u'
hv : v = v'
⊢ length (Walk.copy p hu hv) = length p
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' : V
p : Walk G u' v'
⊢ length (Walk.copy p (_ : u' = u') (_ : v' = v')) = length p

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'
⊢ length (Walk.copy p (_ : u' = u') (_ : v' = v')) = length p
Tactic:
rfl
State after:
no goals