Browsing by Author "Stokes, Tim E."

Now showing items 11-15 of 30

  • Generalised domain and E-inverse semigroups

    Stokes, Tim E. (Springer, 2018)
    A generalised D-semigroup is here defined to be a left E-semiabundant semigroup S in which the \overline{\mathcal R}_E-class of every x\in S contains a unique element D(x) of E, made into a unary semigroup. Two-sided ...
  • Groups with fix-set quasi-order

    Stokes, Tim E.; Hawthorn, Ian; Manoharan, Siva (Springer Basel, 2015)
    If X is a set, the fix-set quasiorder on a group of permutations of X is the quasiorder induced by containment of the fix-sets of elements of SX. Axioms for such quasiorders on groups have previously been given. We generalise ...
  • How to generalise demonic composition

    Stokes, Tim E. (Springer Verlag, 2020)
    Demonic composition is defined on the set of binary relations over the non-empty set X, 𝑅𝑒𝑙𝑋, and is a variant of standard or “angelic” composition. It arises naturally in the setting of the theory of non-deterministic ...
  • Identities in the Algebra of Partial Maps

    Jackson, Marcel; Stokes, Tim E. (World Scientific Publishing, 2006)
    We consider the identities of a variety of semigroup-related algebras modelling the algebra of partial maps. We show that the identities are intimately related to a weak semigroup deductive system and we show that the ...
  • Joins of subalgebras and normals in 0-regular varieties

    Stokes, Tim E.; McConnell, N. R. (Springer Basel, 2015)
    In any 0-normal variety (0-regular variety in which {0} is a subalgebra), every congruence class containing 0 is a subalgebra. These “normal subalgebras” of a fixed algebra constitute a lattice, isomorphic to its congruence ...