Math proposition (7)
I believe the answer is:
theorem
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">math proposition</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for theorem that I've seen before include "Deduced formula" , "Algebraic rule" , "Logical proposition" , "Geometrical proposition to be proved" , "Geometric proposition" .)