A generalization of ACP using Belnap's logic.

Alban Ponse Mark van der Zwaag A generalization of ACP using Belnap's logic. 222-235 2007 70 J. Log. Algebr. Program. 2 http://dx.doi.org/10.1016/j.jlap.2006.08.006 db/journals/jlp/jlp70.html#PonseZ07