§ 700. l, n and r are meaningless, as in the original lines.
CHAPTER XIX.
Of Immediate Inference as applied to Complex Propositions.
§ 701. So far we have treated of inference, or reasoning, whether mediate or immediate, solely as applied to simple propositions. But it will be remembered that we divided propositions into simple and complex. I t becomes incumbent upon us therefore to consider the laws of inference as applied to complex propositions. Inasmuch however as every complex proposition is reducible to a simple one, it is evident that the same laws of inference must apply to both.
§ 702. We must first make good this initial statement as to the essential identity underlying the difference of form between simple and complex propositions.
§ 703. Complex propositions are either Conjunctive or Disjunctive (§ 214).
§ 704. Conjunctive propositions may assume any of the four forms, A, E, I, O, as follows—
(A) If A is B, C is always D.
(E) If A is B, C is never D.
(I) If A is B, C is sometimes D.
(O) If A is B, C is sometimes not D.
§ 705. These admit of being read in the form of simple propositions, thus—
(A) If A is B, C is always D = All cases of A being B are cases of C
being D. (Every AB is a CD.)