Problem Set 3
Due Date: Thurs, Feb 13
Please read Smullyan, Chapter XI, p. 101-108 for Thurs, Feb 13
- Translate the following arguments into propositional formulas and prove
them right or wrong:
- If either wages or prices are raised, there will be
inflation. If there is inflation, then either Congress must
regulate it or the people will suffer. But if the people suffer,
then congressmen will be unpopular. However, Congress does not
regulate inflation and congressmen are not unpopular. Therefore,
wages do not rise.
- Jones has filed a lawsuit against Rogers because of a contract.
Jones will win the lawsuit if and only if Rogers has entered
into the contract, the contract is legal, and Rogers has not
performed the contract. Rogers has entered into the contract
only if he has accepted Jones' offer. But, in fact, Rogers has
not accepted Jones' offer. Therefore Jones will lose the
lawsuit.
- Solve the Exercise on p. 30, items 2
- State the tableau rules for the joint denial connective
(c.f. problem set 1) and prove that they give a correct
and complete proof system for propositional logic.
Juanita Heyerman
2003-02-05