Page 7 - Chapter 2

• The connective “or”

(a) I left for Spain on Monday or I left for Spain

on Friday.
(b) I passed math or I failed French”

Note:

Case (a): Both could not have occurred. “or” is an

excusive sense in this case.

Case (b): Both could have occurred. “or” is an
inclusive sense in this case.

In mathematics and computer science. We agree

to use the connective “or” in inclusive manner.

• Example:

Form the disjunction of p and q

p: 2 is a positive integer

q : sqrt(2) is a rational number
Algorithm for
Solution:
making Truth Table:

p V q: 2 is a positive integer or

sqrt(2) is a rational number.

Since p is true, p V q is true,
even through q is false.