lean2/tests/lean/slow/tactic1.lean
Leonardo de Moura 08718e33dc refactor(builtin): only load the kernel and natural numbers by default
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-12-30 13:35:37 -08:00

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1.3 KiB
Text

Import int.
Definition double {A : Type} (f : A -> A) : A -> A := fun x, f (f x).
Definition big {A : Type} (f : A -> A) : A -> A := (double (double (double (double (double (double (double f))))))).
(**
-- Tactic for trying to prove goal using Reflexivity, Congruence and available assumptions
local congr_tac = Repeat(OrElse(apply_tac("Refl"), apply_tac("Congr"), assumption_tac()))
-- Create an eager tactic that only tries to prove goal after unfolding everything
eager_tac = Then(-- unfold homogeneous equality
Try(unfold_tac("eq")),
-- keep unfolding defintions above and beta-reducing
Repeat(unfold_tac() .. Repeat(beta_tac())),
congr_tac)
-- The 'lazy' version tries first to prove without unfolding anything
lazy_tac = OrElse(Then(Try(unfold_tac("eq")), congr_tac, now_tac()),
eager_tac)
**)
Theorem T1 (a b : Int) (f : Int -> Int) (H : a = b) : (big f a) = (big f b).
eager_tac.
done.
Theorem T2 (a b : Int) (f : Int -> Int) (H : a = b) : (big f a) = (big f b).
lazy_tac.
done.
Theorem T3 (a b : Int) (f : Int -> Int) (H : a = b) : (big f a) = ((double (double (double (double (double (double (double f))))))) b).
lazy_tac.
done.