We divide the class of infinite computable trees into three
types. For the first and second types, 0' computes a nontrivial
self-embedding while for the third type 0'' computes a nontrivial
self-embedding. These results are optimal and we obtain partial
results concerning the complexity of nontrivial self-embeddings of
infinite computable trees considered up to isomorphism. We show
that every infinite computable tree must have either an infinite
computable chain or an infinite Π01
antichain. This result is optimal and has connections to the
program of reverse mathematics.
@article{1199649898,
author = {Binns, Stephen and Kjos-Hanssen, Bj\o rn and Lerman, Manuel and Schmerl, James H. and Solomon, Reed},
title = {Self-Embeddings of Computable Trees},
journal = {Notre Dame J. Formal Logic},
volume = {49},
number = {1},
year = {2008},
pages = { 1-37},
language = {en},
url = {http://dml.mathdoc.fr/item/1199649898}
}
Binns, Stephen; Kjos-Hanssen, Bjørn; Lerman, Manuel; Schmerl, James H.; Solomon, Reed. Self-Embeddings of Computable Trees. Notre Dame J. Formal Logic, Tome 49 (2008) no. 1, pp. 1-37. http://gdmltest.u-ga.fr/item/1199649898/