flex Expert System Toolkit - LPIS

9. Flex Predicates 125
disprove( +Goal )
enable_rules
Dereference each of the arguments of the Goal and then try to disprove it.
If there is a Prolog program for the Goal, then that program is run together
with negation-as-failure. Otherwise, the workspace is searched for a
matching exception (see new_exception/1), or a check is made that
there are no matching facts (see new_fact/1).
Example
?- disprove( X=or([a,b,c]) ).
no
?- disprove( likes( X, Y) ).
X = mary, Y = fred
Re-enable all rules which have previously been disabled.
enable_rules( +Names )
Re-enable all of the rules in Names which may have been previously disabled
(see disable_rules/1). They can now be considered as potential rules to
fire.
Example
enable_rules( [fill_B_from_A] )
equality( +Term1,+Term2 )
The two terms are dereferenced and the resulting terms equated. If the
equate fails (or there is backtracking into equality/2) then alternative
dereferenced values will be equated.
Example
?- equality( pressure, high ).
no
?- equality( temperature, 2*50 ).
yes
?- equality( X, or([a,b,c]) ).
X = a
X = b
X = c
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