* money pump
* implement depth-first Warp test? (to get preference order)
* lowmem version for Floyd-Warshal?
* option to see all warp, garp, sarp violations?
* use std::vector in more functions (upper bound CP)
* iterative version of depth-first Sarp test

* Kuan-Pin Lin, Stan Perry, Computer Science in Economics and Management, 1988, Volume 1, Issue 2, pp 97-111, A logic programming approach to revealed preference theory

