Abstract fairness and semantics

Fairness of a program execution, c, usually expresses that all objects which are sufficiently often enable have to occur also sufficiently often in c. There exists a well-known strong equivalence between fair program executions, #PI#_3"0-formulae, and convergence of initial program executions. However, these results cannot be applied to a study of 'fair semantics' of programs, as such a fair semantics is a #SIGMA#_1"1-formula in general. The main reason therefore is that a semantics does not tell which objects are enabled - only the actually occurring objects are usually seen in semantics. Here we study on a very abstract level some quite natural requirements for semantics s.t. fair semantics with invisible 'enabledness' can also be characterized with topological techniques. (orig.)Available from TIB Hannover: RO 6844(1995,16) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman