Write definitions using elementhood tests for the following

Write definitions using elementhood tests for the following sets:

a. {5, 10, 15, 20, 25, 30, ...}

b. {-4, -3, -2, -1, 0, 1, 2, 3}

c. {2, 3, 5, 7, 11, 13, 17, 19, 23, ...}

Solution

The notation {A / B} means the set of all things A such that B is true.

a).{5n / nN } (or) {xRx=5y for some yN}

b). { (n-5) / nN} (or) {xRx=(y-5) for some yN}

c). { n / nPrime Numbers} (or) {xRx=y for some yPRIME NUMBERS}