Revision as of 13:17, 22 November 2023 edit Robert Kowalski (talk \| contribs) Extended confirmed users 593 edits Added the example removed from the Wikipedia page on logic programming ← Previous edit		Revision as of 13:21, 22 November 2023 edit undo Robert Kowalski (talk \| contribs) Extended confirmed users 593 edits m →Example 4 Next edit →
Line 92: ===Example 4=== The following example shows how abduction can be to ~~interpret~~simulate [[negation as failure]] ~~as a form of abductive reasoning~~:<ref>Eshghi, K. and Kowalski, R.A., 1989, June. Abduction Compared with Negation by Failure. In ICLP (Vol. 89, pp. 234-255).</ref> <syntaxhighlight lang="prolog"> canfly(X) :- bird(X), normal(X). Line 101: </syntaxhighlight> Here the predicate <kbd>normal</kbd> is abducible, and the abducible condition <kbd>normal(X)</kbd> corresponds to the negative literal <kbd>not(abnormal(X))</kbd> in normal logic programming. The constraint <kbd>false :- normal(X), wounded(X)</kbd> ensures that the abducible condition is not assumed when the condition <kbd>wounded(X)</kbd> also holds. This is like ensuring that <kbd>not(abnormal(X))</kbd> succeeds when <kbd>wounded(X)</kbd> fails. The goal of explaining the observation <kbd>canfly(mary)</kbd> has the solution <kbd>normal(mary)</kbd>. The same solution justifies the answer <kbd>X = mary</kbd> for the goal:

Abductive logic programming: Difference between revisions