Chapter 15 introduces paraconsistent logics, logics that tolerate contradictions. These logics provide an interesting response to the paradoxes we have discussed and provide an alternative account of reasoning in inconsistent or incomplete domains. Also presented is addition with ordinal numbers.

Formal topics:

• Truth-functional connectives in paraconsistent logic
• Paraconsistent entailment
• Paraconsistent quantification

Informal topics:

• Rabbinic logic (on the web)
• Relevance in the law (on the web)

Supplementary topics:

• The hypergame paradox
• The paradox of the knower
• Schedule D
• Puzzles