Intrinsic Logical Operations

A LOGICAL or boolean expression returns a .TRUE. / .FALSE. result. The following operators are valid with LOGICAL operands,

• .NOT. -- monadic negation operator which gives .TRUE. if operand is .FALSE., for example, .NOT.(a .LT. b).
• .AND. -- logical and operator. .TRUE. if both operands are .TRUE..
• .OR. -- logical or operator. .TRUE. if at least one operand is .TRUE..
• .EQV. -- .TRUE. if both operands are the same.
• .NEQV. -- .TRUE. if both operands are different.

The following are examples of logical expressions,

    REAL :: a, b, x, y
    LOGICAL :: l1, l2
     ...
    l1 = (.NOT.(x.EQ.y.AND.a.EQ.b))
    l2 = (l1.EQV.((x.GT.a.OR.y.LT.b).NEQV.a.EQ.b))