Currently, we can enter multiple keywords in the text slot and one formula in the formula slot. This poses two restrictions:
we cannot enter key phrases (I think), since their parts are interpreted as different keywords. But I am not sure, see #88
we cannot enter multiple formulae (this is the more important part of this issue). I think we should allow multiple formula slots (adding one by a + button) with their own previewers.
We should probably when we have clarified the search semantics (see #90)
Currently, we can enter multiple keywords in the text slot and one formula in the formula slot. This poses two restrictions: