Question

Let A be the set of words containing the letter s, and let B be

the set of words containing the letter t.

Express the following set as a combination of sets A and B.

a. The set of words that do not contain the letter s

b. The set of words containing the letter s and the letter t

c. The set of words containing an s, but not a t

d. The set of words that do not contain the letters s and t

e. The set of words containing the letter s or t, but not both

Answer 1

a) $\neg A$

b) $A⋂B$

c) $A⋂\neg B$

d) $\neg A⋂\neg B$

e) $(A/B)∪(B/A)$