Classifying and Comparing Statements
	Chapter 4.4 & 4.5
	A First Course in Logic
Tautology
	Whenever the truth table for a statement is true on every row, the statement is a tautology.
SelfContradictory
	Whenever the truth table for a statement is false on every row, the statement is a self-contradictory.
Contingency
	Whenever the truth table for a statement is true on some rows and false on other rows, the statement is contingent.
Consistent
	Whenever the truth table for 2 or more statements is true on at least one row then the statements are consistent.
Inconsistent
	Whenever the truth table for 2 or more statements is NOT true on at least one row then the statements are inconsistent.
Implication
	We say that one statement implies another, if whenever the first is true, the second is true.
Equivalence
	Two statements are equivalent if each implies the other.
	Equivalence can be thought of as mutual implication.