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Diamond embeddings into the enumeration degrees

Published online by Cambridge University Press:  27 October 2010

ANDREA SORBI ,
GUOHUA WU  and
YUE YANG
ANDREA SORBI
Affiliation:
Department of Mathematics and Computer Science ‘Roberto Magari’, University of Siena, 53100 Siena, Italy Email: sorbi@unisi.it URL: http://www.dsmi.unisi.it/~sorbi/
GUOHUA WU
Affiliation:
Division of Mathematical Sciences, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore Email: guohua@ntu.edu.sg URL: http://www3.ntu.edu.sg/home/guohua/
YUE YANG
Affiliation:
Department of Mathematics, National University of Singapore, 119076 Singapore Email: matyangy@nus.edu.sg URL: http://www.math.math.nus.edu.sg/~matyangy/
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Abstract

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We show that the diamond lattice can be embedded into the Σ02 enumeration degrees preserving 0 and 1, with atoms one high and Π01, and the other one low.

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