flex Expert System Toolkit - LPIS

9. Flex Predicates 147
Attribute of the Frame; in addition, the Context (a Prolog call) must
also hold before the watchdog can be invoked.
The Check occurs immediately before the access. Indeed, the access will
only be allowed if the Check succeeds. If the Check fails, then the Action
(a Prolog call) is initiated and the access (a call to isa_slot/3) will also fail.
Example
new_watchdog(
security,
balance,
account,
outside_office_hours,
comparison(>,@(classification,user),99),
fail ) .
nospy_chain
Disable the tracing of the forward chaining engine by removing any
spypoints.
nospy_fact( ?Name )
Remove any spypoints that have been set for the fact of the given Name.
Example
nospy_fact( likes ) .
nospy_rule( ?Name )
Remove any spypoints that have been set on the named rule. If the Name is
a variable then spypoints are removed from all the rules.
Example
nospy_rule( _ ) .
nospy_slot(?Attribute, ?Frame )
Remove any spypoints which may have been set for the Attribute and
Frame.
Example
nospy_slot( colour, _ ) .
once(+Name,+Names,-Newnames)
This is a built-in program for re-organising the rule agenda after each cycle
of the forward chaining engine. The most recently fired rule is removed from
flex toolkit
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