http://dswarmsikhttkg7jgsoyfiqpj3ighupfrvuz5ri3lu5q2dlqyrpgk7ad.onion/notes/lsg.html
(Huth, Michael and Ryan, Mark, 2004) 13.16. modus ponens From Latin, “method of putting by placing”. The first to explicitly describe the argument form modus ponens was Theophrastus, along with modus tollens .