Boolean Connectors
AND: & or a space.
e.g. "word & word2", "word word2"
OR: | (AltGr 6)
e.g. "word1 | word2"
NOT: - or !
e.g. "word1| word2 - word3"
Other boolean connectors:
^: word at the beginning.
$: word at the end.
(...) to combine connectors.