Sergey,

This is an interesting question and I can't provide an explanation. _TALLY returns 1 whether the condition in the WHERE clause is EOF("RCursor") or !EOF("RCursor"). It also returns 1 when the subquery is used by itself. It returns 0 when both parts of the WHERE clause are included regardless of the EOF() condition.

!EOF("RCursor") returns .F. prior to the execution of the UPDATE statement. So perhaps there is an issue with use of the EOF() function with the optional alias (if you substitute .F. in place of the expression !EOF("RCursor"), _TALLY returns 0).

John