#### Filter Results:

- Full text PDF available (5)

#### Publication Year

2004

2016

- This year (0)
- Last 5 years (2)
- Last 10 years (4)

#### Publication Type

#### Co-author

#### Journals and Conferences

#### Key Phrases

Learn More

- James D. Mitchell, Michal Morayne, Yann H. Péresse, Martyn Quick
- Ann. Pure Appl. Logic
- 2010

Let ΩΩ be the semigroup of all mappings of a countably infinite set Ω. If U and V are subsemigroups of ΩΩ, then we write U ≈ V if there exists a finite subset F of ΩΩ such that the subgroup generated by U and F equals that generated by V and F . The relative rank of U in ΩΩ is the least cardinality of a subset A of ΩΩ such that the union of U and A… (More)

We consider naturally occurring, uncountable transformation semigroups S and investigate the following three questions. (i) Is every countable subset F of S also a subset of a finitely generated subsemigroup of S? If so, what is the least number n such that for every countable subset F of S there exist n elements of S that generate a subsemigroup of S… (More)

- Zak Mesyan, James D. Mitchell, Michal Morayne, Yann H. Péresse
- Math. Log. Q.
- 2012

Though still a relatively young subject within discrete mathematics, the study of pattern classes of permutations is one of the fastest growing and is useful in theoretical computer science as well as various areas of mathematics. There are two commonly used forms of notation for permutations: a1a2 . . . an denotes the permutation which sends i to ai for i… (More)

- J. Hyde, J. Jonusas, James D. Mitchell, Yann H. Péresse
- J. London Math. Society
- 2016

In this paper, we consider the group Aut(Q,≤) of order-automorphisms of the rational numbers, proving a result analogous to a theorem of Galvin’s for the symmetric group. In an announcement, Khélif states that every countable subset of Aut(Q,≤) is contained in an N-generated subgroup of Aut(Q,≤) for some fixed N ∈ N. We show that the least such N is 2.… (More)

- ‹
- 1
- ›