ASK-INSTANCE-VALUE ================== syntax: (ask-instance-value <evaluates-to relation-name> <evaluates-to instance-spec> [:read-dependents {T | NIL | Var}] [:if-undetermined {T | NIL | Var}]) This function returns the first element of the value set of an instance relation or NIL. If ':if-undeter- mined' is not set to NIL, then a 'if-undetermined- action' will be started before the relation value is found. If ':read-dependents' is not set to NIL, then the read-dependents will be informed after the rela- tion value is found. example: >(ask-instance-value 'place louvre) #<capital-city Paris>