author | nipkow |
Fri, 29 Nov 1996 15:11:37 +0100 | |
changeset 2281 | e00c13a29eda |
child 4423 | a129b817b58a |
permissions | -rw-r--r-- |
2281 | 1 |
(* Title: HOL/Integ/IntRingDefs.thy |
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ID: $Id$ |
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Author: Tobias Nipkow and Markus Wenzel |
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Copyright 1996 TU Muenchen |
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*) |
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open IntRingDefs; |
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goalw thy [zero_int_def,zdiff_def] "(zero-x)+(x::int) = zero"; |
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by(Simp_tac 1); |
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qed "left_inv_int"; |
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goalw thy [zero_int_def,zdiff_def] "x-y = (x::int) + (zero-y)"; |
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by(Simp_tac 1); |
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qed "minus_inv_int"; |