lean4-htt/tests/lean/run/eq6.lean
2016-09-20 08:32:37 -07:00

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Text

open list
definition appd {A : Type} : list A → list A → list A
| nil l := l
| (h :: t) l := h :: (appd t l)
theorem appd_nil {A : Type} (l : list A) : appd nil l = l :=
rfl
theorem appd_cons {A : Type} (h : A) (t l : list A) : appd (h :: t) l = h :: (appd t l) :=
rfl
example : appd ((1:nat) :: 2 :: nil) (3 :: 4 :: 5 :: nil) = (1 :: 2 :: 3 :: 4 :: 5 :: nil) :=
rfl