In the monumental paper MIP*=RE five authors, Zhengfeng Ji, Anand Natarajan, Thomas Vidick, John Wright, and Henry Yuen, managed to show that two complexity classes: RE and MIP* do in fact coincide. My impression is that every theorem establishing an equality of two complexity classes is a major result (since it is usually notoriously difficult to equate two complexity classes) but I find this one particularly interesting, since the class of RE languages contains the (in?)famous halting problem. I would like to create some sort of a mental picture regarding what this result in fact tells us: since the halting problem is in the background I'm aware that there is a risk to become overenthusiastic and claim that this theorem would give us a tool to solve undecidable problems. I suspect that this is *not* the case. Still I'm wondering

What is the possible impact of this result on decidability issues and/or logic/proof theory in general?

I do not have enough expertise in complexity theory, proof theory and logic to be able to formulate my question more precisely but very roughly what I have in mind is that maybe there is some undecidable problem on which now we can shed some more light and get some *evidence* or *reasons* to postulate it as an axiom? Or maybe this result could serve as a motivation to develop some new definition of provability? Forgive me if I'm sounding like a crackpot (I'm afraid that I am)—my interest in this theorem came from operator algebras and Connes embedding cojecture which was solved in this very unexpected way.

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