Lewis Carroll Exercises 39–44 are from problems in Lewis Carroll’s book Symbolic Logic. Write each premise in symbols, and then give a conclusion that uses all the premises and yields a
valid argument. Source: The Complete Works of Lewis Carroll.
Let h be “one is honest,” p be “one is a pawnbroker,” b be “one is a promise breaker,” t be “one is trustworthy,” c be “one is very communicative,” and w be “one is a wine drinker.”
a. Promise breakers are untrustworthy.
b. Wine drinkers are very communicative.
c. A man who keeps his promise is honest.
d. No teetotalers are pawnbrokers. (Hint: Assume “teetotaler”
is the opposite of “wine drinker.”)
e. One can always trust a very communicative person.
f. Give a conclusion that yields a valid argument.