When a size error condition occurs, the value of those resultant- identifier(s) affected is undefined. Any subsequent use of the resultant-identifier(s) affected is also unpredictable in effect. Values of resultant-identifier(s) for which no size error condition occurs are unaffected by size errors that occur for other resultant-identifier(s) during execution of this operation.
After completion of the arithmetic operation, control is transferred to the end of the arithmetic statement and the NOT ON SIZE phrase, if specified, is ignored.
Results of division by zero, when no ON SIZE ERROR is specified, are unpredictable. You can avoid this by using the CHECKDIV Compiler directive and O RTS switch.