Evaluate "++' in a compute expression

[Ralph Linkletter]

What would be the evaluation of the "++" below
It isn't "C" - It's COBOL
It compiles with Micro Focus, Fujitsu, and GnuCOBOL
The execution acts upon it as if there is only a single '+'
I have never purposefully written such a statement

COMPUTE IBZ-REFMOD-STRT = IBZ-REFMOD-STRT
++ ((IBZ-W1 - 1) * USYM-ELEM-LEN) + 1

Compiling PLUSPLUS.COB...
Compilation complete with no errors
Build finished with no errors.
Completed in 1 seconds

[Denis HUGONNARD-ROCHE]

Hi Ralph in fact the first + of the ++ expression is the addition operation . The second plus is interpreted as the sign of the field ie positive

here a little program to illustrate that .

       IDENTIFICATION DIVISION.
       PROGRAM-ID . testplus .
      *>----------------------------------------------------------------
      *>
       ENVIRONMENT DIVISION.
       DATA DIVISION .
       WORKING-STORAGE  SECTION.


       01  I             PIC S9(04) BINARY .
       01  J             PIC S9(04) BINARY .
       01  K             PIC S9(04) BINARY .
       01  Z             PIC S9(04) BINARY .

       PROCEDURE DIVISION .
      *>
           MOVE 1 TO  I .
           MOVE 2 TO  J .
           MOVE 3 TO  K .
      *>
           COMPUTE Z = I ++J + K END-COMPUTE.
           DISPLAY 'Z = ' Z END-DISPLAY .
      *>
           COMPUTE Z = I +-J + K END-COMPUTE.
           DISPLAY 'Z = ' Z END-DISPLAY .
      *>
           MOVE -2 TO J .
      *>
           COMPUTE Z = I ++J + K END-COMPUTE.
           DISPLAY 'Z = ' Z END-DISPLAY .
      *>
           COMPUTE Z = I +-J + K END-COMPUTE.
           DISPLAY 'Z = ' Z END-DISPLAY .
      *>
      *>
           GOBACK .

[Ralph Linkletter]

Thank you Denis.
It is obvious thanks to your example.
It is less than obvious when the object of the second plus sign contemplates a more complex expression than a single data element.

Thank you again !