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NOTE 2: When two or more Lessons are to be turned in on the same day, please staple the Lessons separately and turn them in separately.
Due Wednesday, January 30
- Sect. 1:
- What does “ONLY IF” mean? ... Discuss as described below.
As the textbook points out in Section 1, the statement “p ONLY IF q” means the same as “IF p THEN q”. The point of this problem is to understand this in the following “real-life” context, where
p is the statement “I will be rich” and
q is the statement “I win the lottery”.
Discuss, in this context, the difference in meaning between “IF p THEN q” and “IF q THEN p”, and explain why the first of these statements is a better interpretation of “p ONLY IF q” than the second.
As usual in such examples, you have to be generous and make reasonable assumptions when interpreting the given statements; e.g., there is obviously an element of time involved which is not mentioned explicitly. Don't focus on any possible uncertainties (e.g., regarding time) in the given statements, but focus on understanding “only if”.
Do, however, focus on the possible truth values of the given statements and make use of the resulting truth value of the “IF ... THEN ...” statement.
NOTE: As stated on the Course Home Page, all due dates are tentative. Assignments, or parts of assignments, may be postponed to a later date.
Last modified Jan 26, 2008 1:13 PM
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