Yo seem to think that queries of this form are ambiguous, but they are not. Given the set of shirts, and that the subset of 'shirts with stripes' is well-define

Yo seem to think that queries of this form are ambiguous, but they are not. Given the set of shirts, and that the subset of 'shirts with stripes' is well-defined (which you apparently accept, given that you seem to think that 'shirts with stripes' is an unambiguous query (which it is)), then its complement is well-defined; there is no 'Russell's Barber' paradox here, as there is no self-reference.