Two propositions can generate 2×2=4 assignments, and the true value of the propositional formula under each assignment can be 0 or 1, so there are 2× 2× 2 = 16 unequal propositional formulas.

N propositional arguments, that is, there are 2 n lines of truth table and 2 n lines, and each line has two kinds of TorF, so there are 2 (2 n) kinds. 2 n positions, each position has 0 or 1, that is, 2 * 2 * 2 *...* 2, and * * is 2 n times 2, that is, 2 (2 n).

Basic attribute

(1) if x>y, then y < x；; If y

2 If x>y, y & gtz；; Then x & gtz；; (transitivity)

③ if x>y and z is any real number or algebraic expression, then x+z >; y+z； (addition principle, or additivity of inequality in the same direction)

4 If x>y, z>0, then xz & gtyz；; If x>y, z<0, and then xz.