Hello again, Sometimes I misuse indices by not just having them as operands of indexed objects but, for example, as elements of lists. In this case it can be quite useful to be able to substitute them for objects that are not indices. However, this is not really possible because substituting indices by objects that are not indices really substitutes the value. For this reason I introduced a subs_option really_subs_idx that turns this behaviour off. The change is in CVS. Best wishes, Chris