| changeset 8936 | a1c426541757 |
| parent 8935 | 548901d05a0e |
| child 8937 | 7328d7c8d201 |
| 8935:548901d05a0e | 8936:a1c426541757 |
|---|---|
1 (* Title: HOL/ex/IntRingDefs.thy |
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2 ID: $Id$ |
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3 Author: Tobias Nipkow and Markus Wenzel |
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4 Copyright 1996 TU Muenchen |
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5 *) |
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6 |
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7 Goalw [zero_int_def,zdiff_def] "(zero-x)+(x::int) = zero"; |
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8 by (Simp_tac 1); |
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9 qed "left_inv_int"; |
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10 |
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11 Goalw [zero_int_def,zdiff_def] "x-y = (x::int) + (zero-y)"; |
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12 by (Simp_tac 1); |
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13 qed "minus_inv_int"; |