(1) Department of Mathematics, Western Illinois University, Macomb, IL 61455, USA
Abstract:
Let I be a quasimaximal subset of a computable basis of the fully efective vector space V. We give a necessary and sufficient condition for the existence of an isomorphism between the principal filter respectivelly. We construct both quasimaximal sets that satisfy and quasimaximal sets that do not satisfy this condition. With the latter we obtain a negative answer to Question 5.4 posed by Downey and Remmel in [3].Based on the authors Ph.D. dissertation.Mathematics Subject Classification (2000): 03D25, 03C57
. We give a necessary and sufficient condition for the existence of an isomorphism between the principal filter respectivelly. We construct both quasimaximal sets that satisfy and quasimaximal sets that do not satisfy this condition. With the latter we obtain a negative answer to Question 5.4 posed by Downey and Remmel in [3].Based on the author
s Ph.D. dissertation.Mathematics Subject Classification (2000): 03D25, 03C57