FDE and its cousins and expansions
Osnova sekce
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FDE: Belnap's first-degree entailment logic FDE, also known as Belnap and Dunn’s "useful four-valued logic". We cover its extensional, 4-valued semantic, axiomatization and algebraic completeness as well as its frame double-valuation semanitcs and frame completeness.
Expansions of FDE: we look at various expansions with additional connectives (negations, implications, modalities) both from extensional and intensional perspective. In particular, we will see Nelson's paraconsistent logic N4 and Wansing's logic I_4C_4 of constructive negation, and their relation to intitionistic or bi-intuitionistic logic.