Single Idea 13139

[catalogued under 4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / c. Derivation rules of ML]

Full Idea

General tableau rules for implications: a) if σ ¬(X → Y) then σ X and σ ¬Y b) if σ X → Y then σ ¬X or σ Y

Gist of Idea

Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y

Source

M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2)

Book Reference

Fitting,M/Mendelsohn,R: 'First-Order Modal Logic' [Synthese 1998], p.49

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