Page 8 - UAS Media Pembelajaran Berbasis IT e-modul Evri Sariati Pakpahan 4183111061

A. Statements, Open Sentences

1. Statement
Statement is the basic structure in the logic. In mathematics, statement usually called

proposition. Generally, proposition can be defined as follow:

“Proposition is a sentence, which can explain something true or false, but not both”.
Example 1:

a. The products of 3 and 7 are 21
b. All birds can fly

c. There are prime numbers that are even
Examples a and c are statements that have true values, while b are statements that

have false values.

Examples of sentences that are not statements:
a. Hopefully you will go up to class later

b. Would you please close the window?
c. Has Budi eaten?

In mathematical logic, a statement is usually written by the small letters p, q, r, …,
etc. For example:

: All prime numbers are odd

: Jakarta is the capital city of Indonesia
There are 2 bases for determining the truth value of a statement, namely:

a. Empirical basis: if the truth value is determined by observation at a certain

moment.
Example 2:

• Long sister's hair

• The weather will be fine tomorrow
b. Non-empirical basis: if the truth value is determined according to certain rules

or laws. So absolute value is not bound by time and place.