#392 Advanced text search logic problem

[Gareth Owen]

Searching for *RS* in IUPAC Name, 3 in Stars finds 148 answers. To remove the arsenic compounds from the list, I tried:
*RS* in IUPAC Name, NOT *ARS* in IUPAC Name, 3 in Stars.
But instead of finding fewer than 148 answers, it finds almost the entire database (29,079 hits).