IDENTIFICATION DIVISION.
       PROGRAM-ID. TESTNDEF.
       ENVIRONMENT DIVISION.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       >>define VAR-DEF as b'1'
       >>if VAR-NOTDEF is defined
         >>define VAR-DEF as VAR-NOTDEF
       >>end-if
       PROCEDURE DIVISION.
       MAIN SECTION.
       >>if VAR-DEF
           display "VAR-DEF is defined"
       >>else
           display "VAR-DEF is not defined"
       >>end-if
           goback.