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
LAND .LAND. && | expression1 LAND expression2 expression1 .LAND. expression2 expression1 && expression2 | Logical conjunction
LOR .LOR. || | expression1 LOR expression2 expression1 .LOR. expression2 expression1 || expression2 | Logical disjunction