This might be something that only Stack Exchange personnel can answer, but...
When using advanced search terms, if I were looking for all of my questions that have an accepted answer
user:me is:question hasaccepted:yes
would appear to give the exact same results as
since, of course, only questions can have an accepted answer.
From a results standpoint, the
is:question is redundant. But what about on the query back-end? Does
hasaccepted:* already include the same query filter as
is:question? Or does adding
is:question make for a more efficient query by eliminating more records right away? Or does it make no never mind?
In a related vein, is there any reason why
hasaccepted:yes would ever give different results than