11 Single-field Wildcard It is useful to test for the existence of a field within a slot without actually assigning a value to a variable. It is usefu
{"Image DocumentName": "(deftemplate person. (multislot name)", "Image ImageDescription": "(deftemplate person (multislot name) (slot social-security-number)) (deffacts some-people (person (name John Q. Public) (social-security-number )) (person (name Jack R. Public) (social-security-number )) (defrule print-social-security-numbers (print-ss-numbers-for ?last-name) (person (name ?first-name ?middle-name ?last-name) (social-security-number ?ss-number)) => (printout t ?ss-number crlf)) Not referred to by actions on the RHS or other pattern or slots on the LHS of the rule. NO USE! Instead of using a variable, a single-field wildcard can be used when a field is required, but the value is not important.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}