Scenario1 - DYNAMNBR for a step.

Code -

----+----1----+----2----+----3----+----4----+----5----+
//STEP01 EXEC PGM=PROG1,DYNAMNBR=9
//INPUT  DD DSN=....
//OUTPUT DD DSN=....

Explaining Example -

The system should hold the dataset allocations for reuse are - 7. i.e., 9 - 2 (DD statements in the same step).

Scenario2 - DYNAMNBR for a PROC step.

Code -

----+----1----+----2----+----3----+----4----+----5----+
//STEP01 EXEC PROC=MTHPROC,DYNAMNBR.STEP02=9

Explaining Example -

DYNAMNBR specifies that the system should hold the dataset allocations for reuse are - 9 minus the number of DD statements following the STEP02 EXEC statement.

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