THE LOGIC NOTES

Tableau exercises Propositional logic

The following sequents provide practice in the art of constructing tableaux. Answers are given, but of course the idea is to come up with solutions of your own before looking them up. As ever, the answers are not unique: in some cases, alternative tableaux are just as good as the ones given.


p OR q,  NOTq OR r   ⊢   p OR r Try it Answer
p IMP NOTq   ⊢   q IMP NOTp Try it Answer
p IMP NOTq   ⊢   NOTp IMP q Try it Answer
(p AND q) IMP NOTr   ⊢   (p AND r) IMP NOTq Try it Answer
NOTp OR NOTq   ⊢   NOT(p OR q) Try it Answer
NOTp IMP q   ⊢   NOT(p IMP q) Try it Answer
(p IMP q) IMP q   ⊢   (q IMP p) IMP p Try it Answer
(p IMP q) IMP r   ⊢   p IMP (q IMP r) Try it Answer
p IMP (q IMP r)   ⊢   (p IMP q) IMP r Try it Answer
p IMP NOTqq IMP NOTp   ⊢   NOT(p IFF q) Try it Answer
(p AND q) IMP NOT r   ⊢   (r AND NOT p) IMP NOTq Try it Answer
⊢   (p IMP (q IMP r)) IMP ((s IMP q) IMP (p IMP (s IMP r))) Try it Answer
(p AND q) IMP s,  (p AND r) IMP s   ⊢   (p AND NOT s) IMP (q IFF r) Try it Answer
p IFF (q OR r)   ⊢   (p IFF q) OR (p IFF r) Try it Answer
p IFF (q AND r)   ⊢   (p IFF q) AND (p IFF r) Try it Answer
p IFF (q IFF r)   ⊢   (p IFF q) IFF (p IFF r) Try it Answer
p IFF (q IFF r)   ⊢   (p IFF q) IFF r Try it Answer