Comparison Between Two Languages Used to Express Planning Goals: CTL and EAGLE

摘要

The extended goals in non-deterministic domains are often expressed in temporal logic, particularly in CTL and EAGLE. No work has given a formal comparison between EAGLE and CTL on semantics, though it is said that the capability of representing the “intentional” aspects of goals and the possibility of dealing with failure are the main new features of EAGLE w.r.t. CTL. According to the formal semantics for EAGLE and CTL, we prove that all the EAGLE formulas in which only LV1 operators (i.e. the operators representing the “intentional” aspects of goals) appear and some EAGLE formulas including LV2 operators (i.e. the operators dealing with failure and qualitative preferences) can be replaced by some CTL formulas without any change on semantics. Finally, we also find some basic and important goals in non-deterministic domains that exceed the expressive ability of EAGLE.