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Sat 20 Aug, 2011 03:16 pm
These are a list of absolute truths: Statements that are always true.
1. Every statement is either true or false
2. This statement is true or false.
This is an absolute falsity: A statement that is always false.
1. Every statement is false.
Proofs:
1. Let the set A be a set of all the true statements that exist (A= every true statement) and the set B be the set of all false statements that exist (B= every false statement). Then we can have a set E = {A U B}, where E is the set of all true statements and all false statements. Then the statement " All statements that exist are in E" is always true. Thus every statement is either true or false.
2. Let A = This statement is true or false. If A is true, then A is true according to the statement A. If A is false, then A is still true because it is verified by the statement A.
3. Let B =Every statement is false. If B is true, then this contradicts what statement B claims, thus B is false. If B is false, then there exist at least one statement that is true, thus B is false.