Set: pp::colors
  Set: pp::unicode
  Assumed: vec
  Assumed: concat
  Assumed: concat_assoc
  Assumed: empty
  Assumed: concat_empty
  Defined: TypeM
  Assumed: n
  Assumed: v
  Assumed: w
  Assumed: f
  Assumed: p
  Assumed: fax
p (f (v ; w ; empty ; (v ; empty))) ∧ v = cast (to_heq (congr2 vec (Nat::add_zeror n))) (v ; empty)
===>
p (v ; (w ; v))
checking proof
(p (f (v ; w ; empty ; (v ; empty))) ∧ v = cast (to_heq (congr2 vec (Nat::add_zeror n))) (v ; empty)) ==
(p (v ; (w ; v)))