Cf: Theme One Program • Exposition 8
http://inquiryintoinquiry.com/2022/10/08/theme-one-program-exposition-8/
All,
Logical Cacti (cont.)
The abstract character of the cactus language relative to its logical
interpretations makes it possible to give abstract rules of equivalence
for transforming cacti among themselves which partition the space of cacti
into formal equivalence classes. The transformation rules and equivalence
classes are “purely formal” in the sense of being indifferent to the logical
interpretation, entitative or existential, one happens to choose.
Two definitions are useful here:
• A “reduction” is an equivalence transformation which applies in the
direction of decreasing graphical complexity.
• A “basic reduction” is a reduction which applies to a basic connective,
either a node connective or a lobe connective.
The two kinds of basic reductions are described as follows.
• A “node reduction” is permitted
if and only if
every component cactus joined to a node itself reduces to a node.
Node Reduction
https://inquiryintoinquiry.files.wordpress.com/2018/04/cactus-graph-e280a2-…
• A “lobe reduction” is permitted
if and only if
exactly one component cactus listed in a lobe reduces to an edge.
Lobe Reduction
https://inquiryintoinquiry.files.wordpress.com/2018/04/cactus-graph-e280a2-…
That is roughly the gist of the rules. More formal definitions
can wait for the day when we have to explain all this to a computer.
Regards,
Jon