An imperative used to change the value of a dynamic reference. An imperative used to change the pattern denoted by a pattern variable. Multiple assignment An evaluation imperative that causes several assignments. True when two references denote objects that have the same state. True when two references denote the same object.
Procedure call An evaluation imperative that causes invocation of a procedure pattern.
An imperative that controls the flow of executions. For imperative A control structure used to support iteration . A list of imperatives are executed repeatedly while an index steps from 1 up to the number of iterations. A control structure used to support selection . Based on evaluating a condition evaluation and comparing it to the values of a number of selection evaluations, one of a set of imperative-lists is executed.