For Wednesday, read chapter 2, sections 3 and 4. As nongraded homework, do the problems at the end each section. Also try exercises 7.1, C, D, and E on the Power of Logic web tutor: It uses a dot in place of the ampersand. Also, look at the ‘help’ link to see how to enter the symbols.

‘&’ abbreviates ‘and’ and equivalent terms José is a doctor and Martin is a lawyer. (J: José is a doctor; M: Martin is a lawyer) J & M Theresa is poor, even though she is a doctor. (P: Theresa is poor; D: Theresa is a doctor) P & D

‘v’ abbreviates the inclusive ‘either...or...’ and equivalent phrases (inclusive ‘or’ is ‘and/or’) Either Jane is over four years old or over forty pounds. (F: Jane is over four years old; P: Jane is over forty pounds) F v P We often use ‘or’ to mean ‘either...or...but not both’; this is the exclusive ‘or’. We can symbolize it if need be, but the formula is somewhat complex.

Exercises, pp

‘→’ is the arrow; it abbreviates “if...then...” and equivalent constructions If I win the lottery, then I’ll be rich. (W: Rob wins the lottery; R: Rob will be rich) use only one arrow; put the “if” condition (the antecedent) on the left, the “then” condition (the consequent) on the right: write W → R not → W → R

When ‘if’ appears alone (not ‘only if’ or ‘if and only if’) the statement(s) following it should be the antecedent (the left side) of your conditional. The same rule applies to ‘provided that’. Tammy will come to the party, if she’s invited. (P: Tammy will come to the party; I: Tammy is invited to the party) I → P

If she’s invited, Tammy will come to the party. I → P Tammy will come to the party only if she’s invited. (This is taken to mean that she won’t come if she’s not invited.) P → I