IF
The IF statement is used to define conditional procedural code, and can only appear in a METHOD definition. Its syntax is
IF logical_expression THEN list_of_statements ELSE list_of_statements END IF;
or
IF logical_expression THEN list_of_statements END IF;
If the logical expression has a value of TRUE, ASCEND will execute the statements in the THEN part. If the value is FALSE, ASCEND executes the state- ments in the optional ELSE part. It's a good idea to use () to make the precedence of AND, OR, NOT, ==, and != clear to both the user and the system.
See also conditional modelling, SWITCH, WHEN and SELECT.