Beginning with version 4.1.1 of COBOL for AIX, during the conversion of a numeric data item to and from a packed-decimal data item, negative zero is no longer converted to positive zero. Negative zero behaves the same as positive zero computationally.
For example, negative zero compares equal to positive zero. In most cases, negative zero will keep the negative sign when converted from zoned to packed, or vice versa.
Negative zero appears rarely in computation. An example is adding -1 to -99 into a PIC 9(2) field. The result is -0 because the high-order 1 digit is truncated.
