| author | oheimb | 
| Sat, 15 Feb 1997 16:04:33 +0100 | |
| changeset 2626 | 373daa468a74 | 
| parent 2281 | e00c13a29eda | 
| child 4423 | a129b817b58a | 
| permissions | -rw-r--r-- | 
| 2281 | 1 | (* Title: HOL/Integ/IntRingDefs.thy | 
| 2 | ID: $Id$ | |
| 3 | Author: Tobias Nipkow and Markus Wenzel | |
| 4 | Copyright 1996 TU Muenchen | |
| 5 | ||
| 6 | *) | |
| 7 | ||
| 8 | open IntRingDefs; | |
| 9 | ||
| 10 | goalw thy [zero_int_def,zdiff_def] "(zero-x)+(x::int) = zero"; | |
| 11 | by(Simp_tac 1); | |
| 12 | qed "left_inv_int"; | |
| 13 | ||
| 14 | goalw thy [zero_int_def,zdiff_def] "x-y = (x::int) + (zero-y)"; | |
| 15 | by(Simp_tac 1); | |
| 16 | qed "minus_inv_int"; |