is the name of a class of objects known to KnowledgeWorks.
is a variable beginning with
is the name of a slot in the class.
is an expression composed of Lisp data structures and KnowledgeWorks variables.
If variable is unbound a new instance of class class-name is created with the named slots containing the value of the term immediately following the slot name. If variable is bound, that bound instance has its named slots modified to contain the value of the term immediately following the slot name. It is an error if the bound object is not of the named class.