Define <arg1>, <arg2>, …​

The Define instruction is used to determine two or more data elements, separated with a comma, that are later used mainly on the right side of expressions for assignments or logical comparisons:

from 002 xcf log 01

All data elements of the same Define instruction are automatically in logical relation to one another: they are saved in the sequence of list – from left to right – in ascending order – and are thus guaranteed to be unequal and definitely different du­ring subsequent comparisons.