18 lines
363 B
Text
18 lines
363 B
Text
open nat
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definition foo : nat → nat
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| foo zero := begin exact zero end
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| foo (succ a) := begin exact a end
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example : foo zero = zero := rfl
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example (a : nat) : foo (succ a) = a := rfl
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definition bla : nat → nat
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| bla zero := zero
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| bla (succ a) :=
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begin
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apply foo,
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exact a
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end
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example (a : nat) : foo (succ a) = bla (succ (succ a)) := rfl
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