Order:
Disambiguations
Bob A. Dumas [3]B. Dumas [1]
  1.  2
    Discontinuous Homomorphisms of With.Bob A. Dumas - forthcoming - Journal of Symbolic Logic:1-32.
    Assume that M is a transitive model of $ZFC+CH$ containing a simplified $(\omega _1,2)$ -morass, $P\in M$ is the poset adding $\aleph _3$ generic reals and G is P-generic over M. In M we construct a function between sets of terms in the forcing language, that interpreted in $M[G]$ is an $\mathbb R$ -linear order-preserving monomorphism from the finite elements of an ultrapower of the reals, over a non-principal ultrafilter on $\omega $, into the Esterle algebra of formal power series. (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark  
  2.  7
    Gap‐2 morass‐definable η 1 ‐orderings.Bob A. Dumas - 2022 - Mathematical Logic Quarterly 68 (2):227-242.
    We prove that in the Cohen extension adding ℵ3 generic reals to a model of containing a simplified (ω1, 2)‐morass, gap‐2 morass‐definable η1‐orderings with cardinality ℵ3 are order‐isomorphic. Hence it is consistent that and that morass‐definable η1‐orderings with cardinality of the continuum are order‐isomorphic. We prove that there are ultrapowers of over ω that are gap‐2 morass‐definable. The constructions use a simplified gap‐2 morass, and commutativity with morass‐maps and morass‐embeddings, to extend a transfinite back‐and‐forth construction of order‐type ω1 to an (...)
    No categories
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark  
  3.  15
    Order-isomorphic η 1 -orderings in Cohen extensions.Bob A. Dumas - 2009 - Annals of Pure and Applied Logic 158 (1-2):1-22.
    In this paper we prove that, in the Cohen extension of a model M of ZFC+CH containing a simplified -morass, η1-orderings without endpoints having cardinality of the continuum, and satisfying specified technical conditions, are order-isomorphic. Furthermore, any order-isomorphism in M between countable subsets of the η1-orderings can be extended to an order-isomorphism between the η1-orderings in the Cohen extension of M. We use the simplified -morass, and commutativity conditions with morass maps on terms in the forcing language, to extend countable (...)
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   1 citation