Individual variables, object constants, function constants, and relation constants were discussed earlier. A functional term consists of a function constant and an arbitrary number of argument terms, terminated by an optional sequence variable. A list term consists of the listof operator and a finite list of terms, terminated by an optional sequence variable. A set term consists of the setof operator and a finite list of terms, terminated by an optional sequence variable. Quotations involve the quote operator and an arbitrary list expression.
Logical terms involve the if and cond operators.
The if form allows for the testing of a single condition only, whereas the cond form allows for the testing of a sequence of conditions. Quantified terms involve the operators the , setofall , kappa , and lambda . A designator consists of the the operator, a term, and a sentence. A set-forming term consist of the setof operator, a term, and a sentence. A relation-forming term consists of kappa , a list of variables, and a sentence.