Issue1222

Title Add translator option for representing disjunctive formulas using derived variables
Priority feature Status chatting
Superseder Nosy List davidspeck, gabi, jendrik, malte, tanja, travis
Assigned To Keywords
Optional summary
The current translator handles disjunctions in preconditions, effect conditions, and axiom bodies by converting formulas to disjunctive normal form (DNF) and creating one instance for each disjunct. For example, a precondition containing a disjunction results in multiple copies of the same operator. Since the DNF transformation can be exponential in the size of the formula, this approach may lead to an exponential runtime and task size.

In this issue, we plan to add an optional translator option that introduces auxiliary derived variables to decompose disjunctive formulas instead of expanding them into DNF. The resulting translation has polynomial size but requires evaluating the auxiliary variables for each state using axioms.

Created on 2026-07-22.08:20:42 by davidspeck, last changed by davidspeck.

Summary
The current translator handles disjunctions in preconditions, effect conditions, and axiom bodies by converting formulas to disjunctive normal form (DNF) and creating one instance for each disjunct. For example, a precondition containing a disjunction results in multiple copies of the same operator. Since the DNF transformation can be exponential in the size of the formula, this approach may lead to an exponential runtime and task size.

In this issue, we plan to add an optional translator option that introduces auxiliary derived variables to decompose disjunctive formulas instead of expanding them into DNF. The resulting translation has polynomial size but requires evaluating the auxiliary variables for each state using axioms.
Messages
msg12113 (view) Author: davidspeck Date: 2026-07-24.13:37:43
PR: https://github.com/aibasel/downward/pull/297
History
Date User Action Args
2026-07-24 13:37:43davidspecksetmessages: + msg12113
status: unread -> chatting
2026-07-22 08:20:42davidspeckcreate