Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universal Learning Theory   This encyclopedic article gives a mini-introduction into the theory of
universal learning, founded by Ray Solomonoff in the 1960s and significantly
developed and extended in the last decade. It explains the spirit of universal
learning, but necessarily glosses over technical subtleties.

20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph