Hi Hilmar

>>3) Finally, if the index expression says not accepted, and the expression to be optimized includes ... and not accepted. Since there is an exact match, the index can be used (according to the assumed logic). However, even if this were so, an index created without the NOT will be used in more cases, than one that includes the NOT.<<

Interesting assumptions, but VFP could also specifically exclude "NOT" like this...

AND NOT "NOT" $ indextagexpression

I remember that indexes with FOR conditions don't work by imagining the Rushmore bitmap would not be complete. There'd be less bits than the number of records.