| author | wenzelm | 
| Wed, 17 Mar 1999 16:45:53 +0100 | |
| changeset 6392 | e2ecfd8622ae | 
| parent 5601 | b6456ccd9e3e | 
| permissions | -rw-r--r-- | 
| 5601 | 1  | 
(* Title: HOL/ex/IntRingDefs.thy  | 
| 5078 | 2  | 
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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Goalw [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 [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";  |