It's a math Language Model. Not even sure it's a Large Language Model. (Maybe shares a foundational model with an English LLM; I don't know)
It learns mathematical statements, and generates new mathematical statements, then uses search techniques to continue. Similar to Alpha Go's neural network, what makes it new and interesting is how the NN/LLM part makes smart guesses that drastically prune the search tree, before the brute-force search part.
(This is also what humans do to solve math probrems. But humans are really, really slow at brute-force search, so we really almost entirely on the NN pattern-matching analogy-making part.)