The purpose of this chapter is to understand the interaction between sentences which we have distinguished as ones which bear truth-values in the previous chapter, and certain logical rules of inference. In general, by considering this interaction one might determine whether the emphasis in the Avicennian logical model is on validity or on truth. In Section 1, an attempt is made to distinguish between eight different forms of expressions with truth-values. These forms are subsequently put to the test by determining (a) how they fare with respect to the rules of inference of the Square of Opposition (Section 2), and (b) how they fare with respect to the subsidiary rule of conversion (Section 3). In considering how Avicenna views the results of this test, one might be able to determine how he views a logical model which formalizes expressions with truth-values.