Is ZF a hack?

Is ZF a hack?: Comparing the complexity of some (formalist interpretations of) foundational systems for mathematics

This paper presents Automath encodings (which also are valid in LF/λP ) of various kinds of foundations of mathematics. Then it compares these encodings according to their size, to find out which foundation is the simplest. The systems analyzed in this way are two kinds of set theory (ZFC and NF), two systems based on Church’s higher order logic (Isabelle/Pure and HOL), three kinds of type theo...

The MIFARE Hack

The MIFARE Classic is the most popular RFID chip, used in public transport as well as cafeterias and other applications. This paper gives an overview of which methods were used to re-engineer the chips, from polishing to analyzing the communication. Within this process, various security weaknesses were discovered. Those allow various attacks, which will be shown in the last part of the paper.

The Case Study of a Computer Hack

Weblint: Just Another Perl Hack

Weblint is a utility for checking the syntax and style of HTML pages. It was inspired by lint [15], which performs a similar function for C and C++ programmers. Weblint does not aspire to be a strict SGML validator, but to provide helpful comments for humans. The importance of quality assurance for web sites is introduced, and one particular area, validation of HTML, is described in more detail...

A Model of ZF Set Theory Language

The articles [5], [6], [3], [4], [1], and [2] provide the terminology and notation for this paper. For simplicity we adopt the following convention: k, n will have the type Nat; D will have the type DOMAIN; a will have the type Any; p, q will have the type FinSequence of NAT. The constant VAR has the type SUBDOMAIN of NAT, and is defined by it = { k : 5 ≤ k }. The following proposition is true ...