17 lines
388 B
Text
17 lines
388 B
Text
open list
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variable {A : Type}
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set_option pp.implicit true
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definition app : list A → list A → list A
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| nil l := l
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| (h :: t) l := h :: (app t l)
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theorem app_nil (l : list A) : app nil l = l :=
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rfl
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theorem app_cons (h : A) (t l : list A) : app (h :: t) l = h :: (app t l) :=
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rfl
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example : app ((1:nat) :: 2 :: nil) (3 :: 4 :: 5 :: nil) = (1 :: 2 :: 3 :: 4 :: 5 :: nil) :=
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rfl
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