A companion to Brady's 4-valued relevant logic BN4: The 4-valued logic of entailment E4

作者：Robles Gemma^*; Mendez Jose M^*

来源：Logic Journal of the IGPL, 2016, 24(5): 838-858.

DOI：10.1093/jigpal/jzw011

• Relevant logics
• many-valued logics
• 4-valued logics
• Belnap-Dunn-type semantics
• Brady's logic BN4

Brady's logic BN4 can be viewed as the 4-valued logic of the relevant conditional. The aim of this article is to introduce the logic E4, which can be regarded as the 4-valued logic of (relevant) entailment on the basis of the two following facts: (1) as the logic R-mingle, E4 has the 'quasi-relevance property'; (2) as Anderson and Belnap's logic of entailment E, E4 encloses a sound theory of logical necessity when the necessity operator is introduced via the definition square A=df(A -> A)-> A.

• 出版日期2016-10