on some classes of expansions of ideals in mvalgebras

In this paper, we introduce the notions of expansion of ideals in mvalgebras, (tau,sigma) primary, (tau,sigma)obstinate  and (tau,sigma)boolean  in mv algebras. we investigate the relations of them. for example, we show that every (tau,sigma)obstinate ideal of an mv algebra is (tau,sigma)primary  and (tau,sigma)boolean. in particular, we define an expansion sigma_{y} of ideals in an mvalgebra. a characterization of expansion ideal with respect to sigma_{y} is given. finally, we show that the class c(sigma_{y}) of all constant ideals relative to sigma_{y} is a heyting algebra.