  We deal in this paper with strategical languages of infinite words, that is
those generated by a nondeterministic strategy in the sense of game theory. We
first show the existence of a minimal strategy for such languages, for which we
give an explicit expression. Then we characterize the family of strategical
languages as that of closed ones, in the topological space of infinite words.
Finally, we give a definition of a Nash equilibrium for such languages, that we
illustrate with a famous example.
