proof_theory.elf revision 239352d9aec4bc3823511873533fa812cbe259c7
7ea448352f44eec95bc3e5dcf6f59a4b5dbc5f79Christian Maeder%read "../propositional/proof_theory/minimal.elf".
5de34eba726f63d1522bf17a857309a6208ce0b5Christian Maeder %include ML %open.
5de34eba726f63d1522bf17a857309a6208ce0b5Christian Maeder %include MPLPf %open.
5de34eba726f63d1522bf17a857309a6208ce0b5Christian Maeder ax_◇ : ded ◇ P ⇔ ¬ □ (¬ P).
5de34eba726f63d1522bf17a857309a6208ce0b5Christian Maeder nec : ded P -> ded □ P.
5de34eba726f63d1522bf17a857309a6208ce0b5Christian Maeder ax_k : ded □ (P ⇒ Q) ⇒ □ P ⇒ □ Q.