Logic & Applications

Big logic johndcook.com/blog/applied-l…

Proof maintenance and repair galois.com/blog/2020/12/p…

'Ex falso quodlibet.' From a false assumption, anything follows.

Classic papers in programming languages and logic cs.cmu.edu/~crary/819-f09/

When are formal proofs worth the effort? johndcook.com/blog/2020/12/0…

If you add either the law of the excluded middle or double negation to intuitionistic logic you can derive the other.

“It is not easy, and perhaps not even useful, to explain briefly what logic is.' -- E. J. Lemmon

Dependent Types at Work cse.chalmers.se/~peterd/papers… [pdf]

Logic in physical form youtu.be/txH3K3shIWs

"Do not ask whether a statement is true until you know what it means." -- Errett Bishop

The linear logic connectives ⊕, ⊗, and ! have positive polarity. The connectives &, ⅋, and ? have negative polarity.

Temporal and polymodal logics johndcook.com/blog/2022/01/2…

'It requires a very unusual mind to undertake the analysis of the obvious.' -- Alfred North Whitehead

A modal logic is monotone if □(p∧q) → □p.

The satisfiability problem (SAT) is trivial for formulas in disjunctive normal form (DNF): just evaluate each clause separately.

A Boolean formula can be rewritten in conjunctive normal form (CNF) in linear time.

A brief history of logic cs.rice.edu/~vardi/comp409… [pdf]

Heyting algebra : intuitionistic logic :: Boolean algebra : classical logic

Proofs of false statements johndcook.com/blog/2008/02/0…

DNF-SAT is in P, but putting a SAT problem into DNF takes exponential time.

The American Aristotle aeon.co/essays/charles…