expression
A sequence of operators, operands, and parentheses that can be evaluated to a
single value, usually at run time. In 4GL, an expression should evaluate to a
simple 4GL data type: number (Boolean, integer, floating-point, and
fixed-point), character, or time (DATE, DATETIME, and INTERVAL).
See also Boolean, character, data type, fixed-point, floating-point, integer, interval, operand, operator, precedence, regular expression.