  We present a new language semantics for real-time concurrency. Its
operational models are higher-dimensional timed automata (HDTAs), a
generalization of both higher-dimensional automata and timed automata. We
define languages of HDTAs as sets of interval-timed pomsets with interfaces. As
an application, we show that language inclusion of HDTAs is undecidable. On the
other hand, using a region construction we can show that untimings of HDTA
languages have enough regularity so that untimed language inclusion is
decidable.
