Up a level |
Savateev, Yury (2014). Proof internalization in generalized Frege systems for classical logic. Annals of pure and applied logic, 165(1), pp. 340-356. Elsevier 10.1016/j.apal.2013.07.017
Savateev, Yury (2012). Product-free Lambek calculus is NP-complete. Annals of pure and applied logic, 163(7), pp. 775-788. Amsterdam: Elsevier 10.1016/j.apal.2011.09.017