2014-08-24 19:58:48 -07:00
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import logic
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2014-09-04 18:41:06 -07:00
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open eq
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2014-07-19 09:55:34 +01:00
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section
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2014-10-09 07:13:06 -07:00
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variable {A : Type}
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2014-07-19 09:55:34 +01:00
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theorem T {a b : A} (H : a = b) : b = a
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:= symm H
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2014-10-09 07:13:06 -07:00
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variables x y : A
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variable H : x = y
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2014-07-19 09:55:34 +01:00
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check T H
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check T
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end
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section
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2014-10-09 07:13:06 -07:00
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variable {A : Type}
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2014-07-19 09:55:34 +01:00
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theorem T2 ⦃a b : A⦄ (H : a = b) : b = a
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:= symm H
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2014-10-09 07:13:06 -07:00
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variables x y : A
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variable H : x = y
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2014-07-19 09:55:34 +01:00
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check T2 H
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check T2
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end
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