2 Apr
2016
2 Apr
'16
7:38 p.m.
That Notices article "Fingerprint Databases for Theorems" online at https://www.math.washington.edu/~billey/papers/fingerprints.pdf <https://www.math.washington.edu/~billey/papers/fingerprints.pdf> mentioned by Jim refers to "equivalent theorems" — as mathematicians often do. (It uses a few trig identities that can be derived from each other.) I "know" what this means in an informal sense — that it's not hard to derive each theorem from the other. But does this *really* mean anything in a formal sense? Because at least in one formal sense, *all* provable theorems in a logical system are equivalent. —Dan