Two forms of Problems " § 2. _Given a Pair of Propositions of Relation, which contain between them a Pair of codivisional Classes, and which are proposed as Premisses: to ascertain what Conclusion, if any, is consequent from them._ Rules 60 Examples worked fully " The same worked briefly, as models 64 § 3. _Given a Trio of Propositions of Relation, of which every two contain a Pair of codivisional Classes, and which are proposed as a Syllogism: to ascertain whether the proposed Conclusion is consequent from the proposed Premisses, and, if so, whether it is complete._ Rules 66 Examples worked briefly, as models " pg-xxvi =BOOK VI.= =THE METHOD OF SUBSCRIPTS.= CHAPTER I. _INTRODUCTORY._ Meaning of x_{1}, xy_{1}, &c. 70 '=Entity=' " Meaning of x_{0}, xy_{0}, &c. " '=Nullity=' " The Symbols "+" and "¶" " '=Like=' and '=unlike=' Signs " CHAPTER II. _REPRESENTATION OF PROPOSITIONS OF RELATION._ The Pair of Converse Propositions "Some x are y" = "Some y are x" 71 Three other similar Pairs " The Pair of Converse Propositions "No x are y" = "No y are x" " Three other similar Pairs " The Proposition "All x are y" 72 The Proposition "All x are y" is _Double_, and is equivalent to the two Propositions "Some x exist" and "No x and y'" " Seven other similar Propositions " Rule for translating "All x are y" from abstract into subscript form, and _vice versâ_ " pg-xxvii CHAPTER III. _SYLLOGISMS._ § 1. _Representation of Syllogisms._ Rules 73 § 2. _Formulæ for Syllogisms._ Three Formulæ worked out:-- Fig. I. xm_{0} + ym'_{0} ¶ xy_{0} 75 its two Variants (a) and (b) " Fig. II. xm_{0} + ym_{1} ¶ x'y_{1} 76 Fig. III. xm_{0} + ym_{0} + m_{1} ¶ x'y'_{1} 77 =Table IX.= Formulæ and Rules 78 Examples worked briefly, as models " § 3. _Fallacies._