4 papers
Quasi-fixed points of substitutive systems
Elżbieta Krawczyk
We study automatic sequences and automatic systems generated by general constant length (nonprimitive) substitutions. While an automatic system is typically uncountable, the set of…
Automaticity of uniformly recurrent substitutive sequences
Elżbieta Krawczyk, Clemens Müllner
We provide a complete characterisation of automaticity of uniformly recurrent substitutive sequences in terms of the incidence matrix of the return substitution of the underlying p…
Substitutive systems and a finitary version of Cobham's theorem
Jakub Byszewski, Jakub Konieczny, Elżbieta Krawczyk
We study substitutive systems generated by nonprimitive substitutions and show that transitive subsystems of substitutive systems are substitutive. As an application we obtain a co…
Rado's theorem for rings and modules
Jakub Byszewski, Elżbieta Krawczyk
We extend classical results of Rado on partition regularity of systems of linear equations with integer coefficients to the case when the coefficient ring is either an arbitrary in…