| 1476 |      1 | (*  Title:      Substitutions/setplus.thy
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|  |      2 |     Author:     Martin Coen, Cambridge University Computer Laboratory
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| 968 |      3 |     Copyright   1993  University of Cambridge
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|  |      4 | 
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|  |      5 | Minor additions to HOL's set theory
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|  |      6 | *)
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|  |      7 | 
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|  |      8 | Setplus = Set + 
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|  |      9 | 
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|  |     10 | rules
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|  |     11 | 
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|  |     12 |   ssubset_def    "A < B == A <= B & ~ A=B"
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|  |     13 | 
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|  |     14 | end
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