3. Uses The above two examples are the only statements that constitutes a definition.Either V appears on the left side of an assignment statement, or V goes out of scope. Exactly what constitutes a use is more complex.
	Example 3.1 the appearance of V on the right side of a copy statement	x = V; a[i] = V;
	Example 3.2 the appearance of V within an expression	x = V + 1; V = V + 1; if (V > 3);
	Example 3.3 output of V	print(V);
	Example 3.4 unary expressions	V++;
	Example 3.5 function/procedure parameters or array indices	x = f(v); f(v); print(a[V]);