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─────IF (Arithmetic IF) ────────────────────────────────────────────────────
 
     Action
 
     Transfers control to one of three statement labels, depending on
     the value of <expression>.
 
     Syntax
 
     IF (expression) label1, label2, label3
 
     Parameter              Description
 
     expression             An integer or real expression.
 
     label1, label2,        Labels of executable statements in the same
     label3                 program unit. The same statement label may
                            appear more than once.
 
     Remarks
 
     The arithmetic IF statement transfers control depending on the
     value of expression:
 
     If expression is:  The next statement executed is:
 
     < 0                The statement at <label1>
 
     0                  The statement at <label2>
 
     > 0                The statement at <label3>
 
     GOTO statements may not transfer control into a DO, IF, ELSEIF,
     or ELSE block from outside the block. The $DO66 metacommand can
     override this restriction for DO loops.
 
     See Also: ◄$DO66►
 
     Example
 
           DO 40 j = -1, 1
           n = j
     C     The following statement transfers control to statement 10
     C     for j = -1, to statement 20 for j = 0, and to statement 30
     C     for j = +1.
           IF (n) 10, 20, 30
        10 CONTINUE
           .
           .
           .
        20 CONTINUE
           .
           .
           .
        30 CONTINUE
           .
           .
           .
        40 CONTINUE
                                    -♦-