slides01-13

3 justi ed because the views themselves have no data

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Unformatted text preview: ms with function symbols by equivalent, new predicates that have variables as arguments. 2. Substitute for the EDB" global predicates in terms of the views, but only where no function symbols are introduced into the rules. 3 Justi ed because the views themselves have no data with function symbols, and other predicates have already had all possible forms with function symbols covered by other rules. Example Continued r1: r2: r3: r4 r6: Use manc1X; Y; Z  for mancgX; Y ; Z . 3 No other variants of manc are needed in this simple example. Only r6 can be used for the m subgoal of r1 r5 would introduce function symbols in the head, and we already generated r8, an appropriate variant of r1 where the m subgoal has been uni ed with the pattern of the head of r5 . r1: mancX,Y :- v2 X,Y No suitable replacement for the f subgoal exists. As for r1, it is necessary only to use r6 , yielding: r3: mancX,Y :- v2 X,Z & mancZ,Y These inversion rules will be eliminated. r7: We must: 4 a Use r4 for the f subgoal, which requires that A and X be uni ed because of...
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This document was uploaded on 01/06/2012.

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