% Basic MACE input file for reasoning about modal logics % For further MACE options, see McCune's MACE website % % http://www-unix.mcs.anl.gov/AR/mace/ % % Remove "%" symbol from front of line to activate it (uncomment it) % % Example MACE input: "mace -N 4 -p 1 < hilbert_mace.txt" looks for % models up to size 4, and then prints out the first model found. set(process_input). list(usable). % % Rule of Modus Ponens (Condensed Detachment) -P(i(x,y)) | -P(x) | P(y). % Rule of Necessitation -P(x) | P(L(x)). % % Luka's axioms for classical propositional logic (PL) P(i(i(x,y),i(i(y,z),i(x,z)))). P(i(x,i(n(x),y))). P(i(i(n(x),x),x)). % % Modal Axioms % % K axiom (valid in all normal modal systems) P(i(L(i(x,y)),i(L(x),L(y)))). % % D axiom (seriality) % P(i(L(x),n(L(n(x))))). % % T axiom (reflexivity) % P(i(L(x),x)). % % B axiom (symmetry) % P(i(x,L(n(L(n(x)))))). % % 4 axiom (transitivity) % P(i(L(x),L(L(x)))). % % 5 axiom (euclidean-ness) % P(i(n(L(n(x))),L(n(L(n(x)))))). % % McKinsey's axiom G % P(i(L(n(L(n(x)))),n(L(n(L(x)))))). % % Lob's axiom % P(i(L(i(L(x),x)),L(x))). % % Denials of formulas of interest % % First example on handout -- in classical PL, no modality needed % -P(i(n(n(a)),a)). % % Example 1.40 (page 35) of Blackburn et al % -P(i(n(i(L(a),n(L(b)))),L(n(i(a,n(b)))))). % % D axiom (seriality) % -P(i(L(a),n(L(n(a))))). % % % T axiom (reflexivity) % -P(i(L(a),a)). % % B axiom (symmetry) % -P(i(a,L(n(L(n(a)))))). % % 4 axiom (transitivity) % -P(i(L(a),L(L(a)))). % % 5 axiom (euclidean-ness) % -P(i(n(L(n(a))),L(n(L(n(a)))))). % % McKinsey axiom G % -P(i(L(n(L(n(a)))),n(L(n(L(a)))))). % % Lob's axiom % -P(i(L(i(L(a),a)),L(a))). % % McKinsey's Axiom G % -P(i(L(n(L(n(a)))),n(L(n(L(a)))))). end_of_list.