For example, if we want to find constituents who fit criterion A, who also either fit B and C, OR they fit one of D or E, then we should be able to write:
A
AND ((B
AND C)
OR (D
OR E))

As it is we have to use work-arounds like adding a parenthesis before A, then coming up with another criterion to add to the end of the string, just to close out the initial parenthesis, like the example below. But sometimes there isn't a good extra criterion.

(A
AND (B
AND C)
OR (D
OR E)
AND F)