12,080
edits
Changes
Directory talk:Jon Awbrey/Papers/Differential Logic : Introduction (view source)
Revision as of 21:12, 30 November 2015
, 21:12, 30 November 2015→Operational Representation: + table + 2 paragraphs
<br>
<br>
{| align="center" cellpadding="0" cellspacing="0" style="border-left:1px solid black; border-top:1px solid black; border-right:1px solid black; border-bottom:1px solid black; text-align:center; width:60%"
|- style="height:50px"
| width="12%" style="border-bottom:1px solid black; border-right:1px solid black" |
<math>\cdot\!</math>
| width="22%" style="border-bottom:1px solid black" |
<math>\mathrm{e}\!</math>
| width="22%" style="border-bottom:1px solid black" |
<math>\mathrm{f}\!</math>
| width="22%" style="border-bottom:1px solid black" |
<math>\mathrm{g}\!</math>
| width="22%" style="border-bottom:1px solid black" |
<math>\mathrm{h}\!</math>
|- style="height:50px"
| style="border-right:1px solid black" | <math>\mathrm{e}\!</math>
| <math>\mathrm{e}\!</math>
| <math>\mathrm{f}\!</math>
| <math>\mathrm{g}\!</math>
| <math>\mathrm{h}\!</math>
|- style="height:50px"
| style="border-right:1px solid black" | <math>\mathrm{f}\!</math>
| <math>\mathrm{f}\!</math>
| <math>\mathrm{e}\!</math>
| <math>\mathrm{h}\!</math>
| <math>\mathrm{g}\!</math>
|- style="height:50px"
| style="border-right:1px solid black" | <math>\mathrm{g}\!</math>
| <math>\mathrm{g}\!</math>
| <math>\mathrm{h}\!</math>
| <math>\mathrm{e}\!</math>
| <math>\mathrm{f}\!</math>
|- style="height:50px"
| style="border-right:1px solid black" | <math>\mathrm{h}\!</math>
| <math>\mathrm{h}\!</math>
| <math>\mathrm{g}\!</math>
| <math>\mathrm{f}\!</math>
| <math>\mathrm{e}\!</math>
|}
<br>
This table is abstractly the same as, or isomorphic to, the versions with the <math>\mathrm{E}_{ij}\!</math> operators and the <math>\mathrm{T}_{ij}\!</math> transformations that we took up earlier. That is to say, the story is the same, only the names have been changed. An abstract group can have a variety of significantly and superficially different representations. But even after we have long forgotten the details of any particular representation there is a type of concrete representations, called ''regular representations'', that are always readily available, as they can be generated from the mere data of the abstract operation table itself.
To see how a regular representation is constructed from the abstract operation table, select a group element from the top margin of the Table, and “consider its effects” on each of the group elements as they are listed along the left margin. We may record these effects as Peirce usually did, as a ''logical aggregate'' of elementary dyadic relatives, that is, as a logical disjunction or boolean sum whose terms represent the ordered pairs of <math>\mathrm{input} : \mathrm{output}\!</math> transactions that are produced by each group element in turn. This forms one of the two possible ''regular representations'' of the group, in this case the one that is called the ''post-regular representation'' or the ''right regular representation''. It has long been conventional to organize the terms of this logical aggregate in the form of a matrix:
==Logical Cacti==
==Logical Cacti==