# Vocab question - is there a standard word for a "provable postulate"?

1. ### HJ Farnsworth

129
Hello,

Is there a common word in the standard math vocab list (postulate, axiom, lemma, corollary, proposition, theorem, definition, claim, remark, etc.) for something that will be treated as a postulate for convenience, even though it is known to be provable from previous postulates and assumptions or simply from common math?

The closest things that I can think of are "Assumption" and "Premise", but neither of these seem quite right.

I think that the answer to my question is probably simply, "no, there is not, if you want to just use your own word". But this seems weird to me, as it is something that I run into in textbooks and literature very frequently (i.e., stuff like "The XXX theorem can be shown to follow from unitarity of the blah operator and countability of the blah domain. However, the proof is rather involved, and for the sake of brevity we simply take it as a postulate. The interested reader is referred to [references].") It just seems like there would be a standard word for people to write something more like, "Postulate-like-Thing 1. XXX(footnote for references if desired)."

Thanks for any help that you can give.

-HJ Farnsworth

2. ### micromass

18,536
Staff Emeritus
Just say it is a theorem and say that the proof is beyond the scope of the work.