10.1.4 Algebraic Identities

An algebraic identity performs a substitution using algebraic laws. We list a few:

	1. X := A + 0		   X := A
	2. X := 1 * A		   X := A
        3. Constant * Symbol       Symbol * Constant

Algebraic substitution can substitute one expression in a basic block with another as shown in Example 6.

EXAMPLE 6 Algebraic Substitution

        
         T1 := BB * J - 1           T1 := BB * J - 1
         ...                     ...
         T1 := T1 + 1               T7 := 4 * J