| changeset 252 | a4dc62a46ee4 |
| parent 251 | f04b33ce250f |
| child 253 | 132634d24019 |
| 251:f04b33ce250f | 252:a4dc62a46ee4 |
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1 (* Title: Option.ML |
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2 ID: $Id$ |
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3 Author: Tobias Nipkow |
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4 Copyright 1994 TU Muenchen |
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5 |
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6 Derived rules |
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7 *) |
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8 |
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9 val option_rws = Let_def :: Option.option.simps; |
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10 val SS = arith_ss addsimps option_rws; |
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11 |
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12 val [prem] = goal Option.thy "P(opt) ==> P(None) | (? x. P(Some(x)))"; |
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13 br (prem RS rev_mp) 1; |
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14 by (Option.option.induct_tac "opt" 1); |
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15 by (ALLGOALS(fast_tac HOL_cs)); |
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16 val optE = store_thm("optE", standard(result() RS disjE)); |