Modal logic, an extension of classical logic, investigates the modes of truth such as necessity and possibility. Its development has been closely intertwined with advances in proof theory, a field ...

This is a preview. Log in through your library . Journal Information The Journal of Symbolic Logic (JSL) was founded in 1936 and it has become the leading research journal in the field. It is issued ...

God is by definition a perfect being. It is more perfect to exist than to not exist. Therefore, God exists. Just given these simple ideas, a few axioms, and a fondness for pushing around abstract ...

Girard introduced phase semantics as a complete set-theoretic semantics of linear logic, and Okada modified phase-semantic completeness proofs to obtain normalform theorems. On the basis of these ...

A computer-assisted proof of a 150-year-old mathematical conjecture can at last be checked by human mathematicians. The Four Colour Theorem, proposed by Francis Guthrie in 1852, states that any four ...