The logical operators work on truth (Boolean) values and deliver well-formed boolean values. A non-zero value is considered true, and a zero value is considered false. All logical operators return well-formed truth values of either zero or one.

Operator Syntax Description
LNOT .LNOT. !! LNOT expression
.LNOT. expression
!! expression
Logical negation. See LNOT and !! operators.
LAND .LAND. && expression 1 LAND expression 2
expression 1 .LAND. expression 2
expression 1 && expression 2
Logical conjunction. See LAND and && operators.
LOR .LOR. || expression 1 LOR expression 2
expression 1 .LOR. expression 2
expression 1 || expression 2
Logical disjunction. See LOR and || operators.