Default Timed Concurrent Constraint Programming

d Abstract) We extend the model of [VRV94] to express strong time-outs (and pre-emption): if an event A does not happen through time t, cause event B to happen at time t. Such constructs arise naturally in practice (e.g. in modeling transistors) and are supported in languages such as ESTEREL (through instantaneous watchdogs) and LUSTRE (through the “current” operator). The fundamental conceptual difficulty posed by these operators is that they are non-monotonic. We provide a simple compositional semantics to the non-monotonic version of concurrent constraint programming (CCP) obtained by changing the underlying logic from intuitionistic logic to Reiter’s default logic [Rei80]. This allows us to use the same construction (uniform extension through time) to develop Default Timed CCP (Default tcc) as we had used to develop Timed CCP (tcc) from CCP [VRV94]. Indeed the smooth embedding of CCP processes into Default cc processes lifts to a smooth embedding of tcc processes into Defau...

• Type: Conference
• Year: 1995
• Where: POPL
• Authors: Vijay A. Saraswat, Radha Jagadeesan, Vineet Gupta
• Keywords: Default Tcc, Default Timed CCP, POPL 1995, Programming Languages, Tcc Processes