8 citations · 19 across the 21 of their papers we have counts for
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math.LO2018
Combinatorial principles equivalent to weak induction
Caleb Davis, Denis R. Hirschfeldt, Jeffry L. Hirst +3
We consider two combinatorial principles, and . Both are easily proved in plus induction. We give two proofs of in ${…
math.LO2018
Erdos-Moser and ISigma_2
Henry Towsner, Keita Yokoyama
The first-order part of the Ramsey's Theorem for pairs with an arbitrary number of colors is known to be precisely BSigma03. We compare this to the known division of Ramsey's Theor…
math.CO2018
Some upper bounds on ordinal-valued Ramsey numbers for colourings of pairs
Leszek Aleksander Kołodziejczyk, Keita Yokoyama
We study Ramsey's theorem for pairs and two colours in the context of the theory of -large sets introduced by Ketonen and Solovay. We prove that any -colouring of pairs from…