Dynamic algebras with test

摘要

We generalize some results, known for dynamic algebras, to test algebras. Main results: Every free algebra in the equational class generated by separable test algebras is isomorphic to a Kripke test structure. Consequently, equational classes generated by separable test algebras and by Kripke test structures coincide. In contrast to dynamic algebras, free separable test algebras over finitely many generators do not exist. Epimorphisms in the equational class generated by separable dynamic or test algebras are shown not to be necessarily surjective.