Necessary subalgebras of simple nonintegral semiassociative relation algebras (Q757364)

For arbitrary ordinals \(\kappa\) and \(\lambda\), three algebras \({\mathfrak M}_{\kappa}\), \({\mathfrak M}_{\kappa \lambda}\) and \({\mathfrak N}_{\kappa \lambda}\) are defined, which turn out to be isomorphic to subalgebras of certain relation algebras. The author points out certain properties of these algebras and certain relationships between them. The main theorem states that every nonintegral simple semi-associative relation algebra includes a nontrivial subalgebra isomorphic to one of the six algebras \({\mathfrak N}_{ij}\), \(i\leq j=1,2,3\).