  We consider simulation games played between Spoiler and Duplicator on two
Buchi automata in which the choices made by Spoiler can be buffered by
Duplicator in two different buffers before she executes them on her structure.
Previous work on such games using a single buffer has shown that they are
useful to approximate language inclusion problems. We study the decidability
and complexity and show that games with two buffers can be used to approximate
corresponding problems on finite transducers, i.e. the inclusion problem for
rational relations over infinite words.
