decr/4—return an integer or enumeration slot value decremented by a specified value within a given limit

The decr/4 operation returns an integer or enumeration slot value decremented by a specified value within a given limit. The general syntax for the decr/4 operation is as follows:

$VAL=decr($SLOT,$DECR,$LIMIT)

decr/4 arguments

Use decr/4 to return the value of the slot specified in $SLOT decremented by $DECR, limited to the value $LIMIT in $VAL. For an enumeration, the slot value returned is decremented to the $DECR next lower value, limited to $LIMIT.

The referenced slot itself is not modified.

decr/4 example

$NEWPRIO = decr( $E.mc_priority , 2 , PRIORITY_4 );