Making Belnap's "Useful 4-Valued Logic" Useful

Background and Motivation

• Automated Reasoning
• Classical First-order Logic
• The Need for More Truth Values
• Belnap's FDE Logic

Designing a "Useful" Conditional Connective

• Classical wrong idea
• Classical material implication (→_cmi)
• Constrained conditional (→_con)
• →_cmi vs. →_con

Implementation and Evaluation

• ATP System Implementation
• Some Illustrative Examples
• Evaluation on the TPTP

Conclusion

The End - Any Questions?