Subtracts the contents of n1 from the contents of n2 and stores
the result in n2.

This is equivalent to: n2 = n2 - n1.

Example

DATA NUMBER TYPE P VALUE 3,
RESULT TYPE I VALUE 7.
SUBTRACT NUMBER FROM RESULT.

The field RESULT now contains 4; the value of
NUMBER remains unchanged at 3.

The remarks about conversions and performance under COMPUTE_ARITH apply equally to SUBTRACT.
The runtime required to subtract two numbers of type I or F is
approx. 2 msn (standardized microseconds). For numbers of type P,
about 9 msn are needed.

BCD_FIELD_OVERFLOW: Result field is too small (type P)

BCD_OVERFLOW: Overflow with arithmetic operation (type P)

COMPUTE_INT_MINUS_OVERFLOW: Integer overflow during
subtraction

Non-catchable runtime error

BCD_BADDATA: P field contains no correct BCD format