Math 3000 Quiz #3
Let A be some set of integers.
- Rewrite the statement below using logical symbols and the predicates P(x) = "x is an
even integer" and Q(x) = "x is a square integer".
- State a useful denial of the statement below as an English sentence.
If all the integers of A are either even or squares, then either there is an even integer in A or
all the integers of A are squares.
Solution:
- (
x
A)(P(x)
Q(x))
(
x
A)(P(x))
(
x
A)(Q(x)).
- A denial in symbols is:
(
x
A)(P(x)
Q(x))
(
x
A)(~P(x))
(
x
A)(~Q(x)).
Which can be rendered as:
All the elements of A are either even or squares, but there is no even integer in A and at least one non-square.