Helmut Seidl. A Modal -Calculus for Durational Transition Systems. LICS, pages 128-137, 1996.

Durational transition systems are finite transition systems where every transition is additionally equipped with a duration. We consider the problem of interpreting -formulas over durational transition systems. In case the formula contains only operations minimum, maximum, addition, and sequencing, we show that the interpretation is not only computable but (up to a linear factor) as efficiently computable as the interpretation of -formulas over ordinary finite transition systems.