X-Nico

unusual facts about first-order logic



Harald Ganzinger

Harald Ganzinger (October 31, 1950, Werneck – June 3, 2004, Saarbrücken) was a German computer scientist that together with Leo Bachmair developed the superposition calculus, which is (as of 2007) used in most of the state-of-the-art automated theorem provers for first-order logic.

Prover9

Prover9 is an automated theorem prover for First-order and equational logic developed by William McCune.

SemEval

Senseval-3 looked beyond the lexemes and started to evaluate systems that looked into wider areas of semantics, such as Semantic Roles (technically known as Theta roles in formal semantics), Logic Form Transformation (commonly semantics of phrases, clauses or sentences were represented in first-order logic forms) and Senseval-3 explored performances of semantics analysis on Machine Translations.

Transcendental function

In fact, Alex Wilkie showed that the situation is even worse: he constructed a transcendental function ƒ: R → R that is analytic everywhere but whose transcendence cannot be detected by any first-order method.

Tuple relational calculus

Lacroix and Pirotte proposed domain calculus, which is closer to first-order logic and which showed that both of these calculi (as well as relational algebra) are equivalent in expressive power.


see also