ONT Re: De In Esse Predication
o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
DEIP. Note 2
o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
| [A Boolian Algebra With One Constant] (cont.)
|
| I begin with the description of the notation for conditional
| or "secondary" propositions. The different letters signify
| propositions. Any one proposition written down by itself
| is considered to be asserted. Thus,
|
| A
|
| means that the proposition A is true.
| Two propositions written in a pair are
| considered to be both denied. Thus,
|
| A B
|
| means that the propositions A and B
| are both false; and
|
| A A
|
| means that A is false. We may have pairs of pairs of propositions
| and higher complications. In this case we shall make use of commas,
| semicolons, colons, periods, and parentheses, just as [in] chemical
| notation, to separate pairs which are themselves paired. These
| punctuation marks can no more count for distinct signs of
| algebra, than the parentheses of the ordinary notation.
|
| C.S. Peirce, CP 4.13, untitled paper circa 1880.
o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o