TY  - JOUR
A1  - Aguado, Felicidad
A1  - Cabalar, Pedro
A1  - Fandinno, Jorge
A1  - Pearce, David
A1  - Perez, Gilberto
A1  - Vidal, Concepcion
T1  - Forgetting auxiliary atoms in forks
JF  - Artificial intelligence
N2  - In this work we tackle the problem of checking strong equivalence of logic programs that may contain local auxiliary atoms, to be removed from their stable models and to be forbidden in any external context. We call this property projective strong equivalence (PSE). It has been recently proved that not any logic program containing auxiliary atoms can be reformulated, under PSE, as another logic program or formula without them – this is known as strongly persistent forgetting. In this paper, we introduce a conservative extension of Equilibrium Logic and its monotonic basis, the logic of Here-and-There, in which we deal with a new connective ‘|’ we call fork. We provide a semantic characterisation of PSE for forks and use it to show that, in this extension, it is always possible to forget auxiliary atoms under strong persistence. We further define when the obtained fork is representable as a regular formula.
KW  - Answer set programming
KW  - Non-monotonic reasoning
KW  - Equilibrium logic
KW  - Denotational semantics
KW  - Forgetting
KW  - Strong equivalence
Y1  - 2019
U6  - https://doi.org/10.1016/j.artint.2019.07.005
SN  - 0004-3702
SN  - 1872-7921
VL  - 275
SP  - 575
EP  - 601
PB  - Elsevier
CY  - Amsterdam
ER  -