Cf: Peirce’s 1870 “Logic of Relatives” • Comment 11.11
https://inquiryintoinquiry.com/2014/05/09/peirces-1870-logic-of-relatives-c…
Peirce’s 1870 “Logic of Relatives” • Comment 11.11
https://oeis.org/wiki/Peirce%27s_1870_Logic_Of_Relatives_%E2%80%A2_Part_2#C…
All,
The preceding exercises were intended to beef-up our “functional literacy” skills
to the point where we can read our functional alphabets backwards and forwards and
recognize the local functionalities immanent in relative terms no matter where they
reside among the domains of relations. These skills will serve us in good stead as
we work to build a catwalk from Peirce’s platform of 1870 to contemporary scenes on
the logic of relatives, and back again.
By way of extending a few very tentative planks,
let us experiment with the following definitions.
• A relative term “p” and the corresponding relation P ⊆ X × Y
are both called “functional on rèlates” if and only if
P is a function at X. We write this in symbols as P : X → Y.
• A relative term “p” and the corresponding relation P ⊆ X × Y
are both called “functional on correlates” if and only if
P is a function at Y. We write this in symbols as P : X ← Y.
When a relation happens to be a function, it may be excusable
to use the same name for it in both applications, writing out
explicit type markers like P : X × Y, P : X → Y, and P : X ← Y,
as the case may be, when and if it serves to clarify matters.
From this current, perhaps transient, perspective, it appears
our next task is to examine how the known properties of relations
are modified when aspects of functionality are spied in the mix.
Let us then return to our various ways of looking at relational
composition and see what changes and what stays the same when the
relations in question happen to be functions of various kinds at
some of their domains.
Here is one generic picture of relational composition,
cast in a style that hews pretty close to the line of
potentials inherent in Peirce’s syntax of this period.
Figure 44. Anything that is a P of a Q of Anything
https://inquiryintoinquiry.files.wordpress.com/2022/03/lor-1870-universal-b…
From this we extract the “hypergraph picture” of relational composition.
Figure 45. Relational Composition P ◦ Q
https://inquiryintoinquiry.files.wordpress.com/2022/03/lor-1870-p-e297a6-q-…
All the information contained in these Figures can be
expressed in the form of a constraint satisfaction table,
or “spreadsheet picture” of relational composition.
Table 46. Relational Composition P ◦ Q
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The following plan of study then presents itself: to see what easy mileage
we can get in our exploration of functions by adopting the above templates
as the primers of a paradigm.
Regards,
Jon