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Apr 20, 2013 at 15:30 answer added Paul Taylor timeline score: 3
Apr 18, 2013 at 14:10 vote accept Sencodian
Apr 18, 2013 at 14:09 vote accept Sencodian
Apr 18, 2013 at 14:10
Apr 18, 2013 at 14:09 vote accept Sencodian
Apr 18, 2013 at 14:09
Apr 18, 2013 at 14:03 comment added Joel David Hamkins DK, you mean to say that they are not a group. Frank, the inverse of Ackermann is primitive recursive, but this is not a bijection. But you can fix it up via the even/odd trick as in my argument and also as in DK's link (and those arguments are fundamentally similar).
Apr 18, 2013 at 13:39 comment added Denis Exercise 5.6 in this book claims that bijective primitive functions are a group, i.e. such a function $f$ exists: books.google.co.il/…
Apr 18, 2013 at 13:37 answer added Joel David Hamkins timeline score: 10
Apr 18, 2013 at 13:15 history asked Sencodian CC BY-SA 3.0