demostrar - P V - Q Si :

(1)p → H P

(2)--Q P

(3)s → P , P

(4}H → -Q P

(5)(P ^ Q)→ S P


(6)P → -Q silogismo hipotetico(1,4)

(7)-P modus ponens (6)

(8)-S modus tollens (7,3)

(9)-(P ^ Q) modus tollens(8,5)

(10) - P v -Q demorgan (9)