Implementing real numbers with RZ

With Iztok Kavkler.

Abstract: RZ is a tool which translates axiomatizations of mathematical structures to program specifications using the realizability interpretation of logic. This helps programmers correctly implement data structures for computable mathematics. RZ does not prescribe a particular method of implementation, but allows programmers to write efficient code by hand, or to extract trusted code [...]

On a proof of Cantor’s theorem

The famous theorem by Cantor states that the cardinality of a powerset `P(A)` is larger than the cardinality of `A`. There are several equivalent formulations, and the one I want to consider is

Theorem (Cantor): There is no onto map `A -> P(A)`.

In this post I would like to analyze the usual proof of Cantor’s theorem [...]