Back in 1971, the late physicist Stephen Hawking made an intriguing prediction: The total surface area of a black hole cannot ...

Stephen Hawking’s 50-year-old theorem on how black holes merge together has been successfully tested thanks to huge advances in gravitational wave astronomy, which helped astronomers catch the waves ...

Can you chip in? The Internet Archive is a nonprofit fighting for universal access to quality information. We build and maintain all our own systems, but we don’t charge for access, sell user ...

Abstract: We embed an operational semantics for security protocols in the interactive theorem prover Isabelle/HOL and derive two strong protocol-independent invariants. These invariants allow us to ...

There are over 400 proofs of the Pythagorean Theorem. Some are visual proofs, others are algebraic. This paper features several proofs of the Pythagorean Theorem in different cultures--Greek, Chinese, ...