> No it isn't ... You almost never hear the word "type" spoken in math courses.

You misread me. What I said was that "set theory" is the general mathematical framework exactly equal to what we computer scientists call "type theory". We have completely different ontologies for what are essentially the same thing (the differences listed on Wikipedia are superficial/conventional and IMHO of no relevance here or in the article).

Mathematicians deal with sets, countable or otherwise, algebraic manipulations of them, bijective mappings, etc. Computer scientists operate on domains (types), their operators, functions, etc. These are different terminology for the exact same thing.