replace - replace the value of a slot in a frame
replace slot of frame by value
A predicate that the current value of a slot with a new value. If the slot does not exists, replace is the same as add.
If a slot has been declared multivalued, a replace replaces all values by the new value. In this case, the new value should be a list.
Triggers the if_replaced dæmon.
Given the generic definition of cylinder, some instances can be defined as:
c isa cylinder with height: 2; radius: 4! add red to colour of c?
multivalued, if_replaced, add