This clears <object>'s <prop-name> property. That is the property value becomes `clear' and all further references to this property will use the value of the same property on the parent object. Note that you can only clear inherited properties. Nor is this the same as removing a property; the property continues to exist.
`@clearproperty' can be abbreviated as `@clearp'.
Example:
@create #1 named foo
You now have foo with object number #42 and parent Root Class (#1).
[foo, as a child of #1 has a .description property which starts out clear]
;#1.description
=> ""
;#1.description = "You see nothing special"
=> "You see nothing special"
;#42.description
=> "You see nothing special"
;#42.description = "Something special"
=> "Something special"
[foo.description is now no longer clear; it has a value of its own]
;#1.description = "Boring"
=> "Boring"
;#42.description
=> "Something special"
@clearp foo.description
Property #42.description cleared; value is now "Boring".
[foo.description is now clear again]
;#1.description = ""
=> ""
;#42.description
=> ""