Abstract
AbstractThe aim of being able to reason about quantities, time or space has been the main objective of the many efforts on the integration of propositional planning with extensions to handle different theories. Planning modulo theories (PMTs) are an approximation inspired by satisfiability modulo theories (SMTs) that generalize the integration of arbitrary theories with propositional planning. Parallel plans are crucial to reduce plan lengths and hence the time needed to reach a feasible plan in many approaches. Parallelization of actions relies on the notion of (non-)interference, which is usually determined syntactically at compile time. In this paper we define a semantic notion of interference between actions in PMT. Apart from being strictly stronger than any syntactic notion of interference, we show how semantic interference can be easily and efficiently checked by calling an off-the-shelf SMT solver at compile time, constituting a technique orthogonal to the solving method.
Highlights
The problem of planning, in its most basic form, consists in finding a sequence of actions that allows one to reach a goal state from a given initial state
Planning modulo theories (PMTs) (8) are a modular framework inspired in the architecture of lazy satisfiability modulo theory (SMT), which is the natural extension of Boolean Satisfiability (SAT) when propositional formulas need to be combined with other theories
The possibility of several actions being planned at the same time step, i.e. the notion of parallel plans, can be considered a key idea to reduce plan lengths and the time needed to reach a feasible plan in many approaches
Summary
The problem of planning, in its most basic form, consists in finding a sequence of actions that allows one to reach a goal state from a given initial state. A problem that arises when considering parallel plans is that of interference between actions. Existing works on numeric planning use syntactic or limited semantic approaches to determine interference between actions, in a fairly restrictive way (6; 7; 11). A new relaxed notion of happening execution and a semantic notion of interference in the context of PMT. We prove their correctness, motivate their usefulness with some examples and show how they can be implemented. This paper is an extension of the work (2) presented at the ICAPS 2016 conference We extend it with a precise description of how interference detection is implemented and by adding detailed experiments. An appendix is included with a Planning Domain Definition Language (PDDL) model of an introduced planning domain, detailed experiments and proofs of auxiliary lemmas
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
