Answer to Question #190958 in Discrete Mathematics for Maaz

Question

Let W(x, y) mean that student x has visited website y, where the domain for x

consists of all students in your school and the domain for y consists of all

websites. Express each of these statements by a simple English sentence.

a) W(Sarah Smith, www.att.com)

b) ∃xW(x, www.imdb.org)

c) ∃yW(José Orez, y)

d) ∃y(W(Ashok Puri, y) ∧ W(Cindy Yoon, y))

e) ∃y∀z(y ≠ (David Belcher) ∧ (W(David Belcher, z) → W(y,z))

f) ∃x∃y∀z((x ≠ y) ∧ (W(x, z) ↔ W(y, z)))

Answer 1

Given,

"W(x,y)="\\text{Student x has visited website y}""

Domain of x = All student in your school

Domain of y = All websites

RESULT

(a) Student Sarah Smith has visited the website www.att.com.

(b) There is a student in your school that has visited the website www.imbd.org.

(c) There is a website that José Orez has visited.

(d) There is a website that Ashok Puri and Cindy Yoon have both visited.

(e) There is a student in your school, beside David Belcher, that has visited all websites that David Belcher visited.

(f) There are two different students in your class that have visited the same websites.