
Recent Posts
Recent Comments
Archives
Categories
 Category Theory
 compressing and summarizing
 digraph theory
 expository
 felicities
 gnarliness
 hazardousnesses
 Higher trees
 infelicities
 Kalai trees
 kindofacycle
 logic
 mathematical aphorisms
 Mathematics
 News
 Olds
 Research
 Silviculture
 Simplicial complexes
 Structure theory
 Technology.
 Uncategorized
 Vignettes.
Meta
Category Archives: Structure theory
Higher Trees Today. Part 0.
For the time being, the installments of the serial ‘Higher Trees Today’ will focus on three kinds of higher trees: Contractible Spaces of Choices (c.s.c.) Diestel–Oum decompositions (d.o.d.) Kalai trees (k.t.) MasbaumVaintrob trees (m.v.t.) Of course, while the latter three … Continue reading
Vignettes. Part 1. Complete Graphs via rightadjoints to forgetting.
The following is widely, though not widelyenoughknown. Let a category of graphs of your choice. Probably any reasonable category of graphs will work for you, mutatis mutandis, as they say, provided that the morphisms of are (at least easily interpretable … Continue reading
Posted in Category Theory, Mathematics, Olds, Structure theory, Vignettes.
Leave a comment
Shaping by pruning: one shapechanging leaf implies infinitelymany shapes obtainable by finitelyoften chopping off leaves.
We start with the shape of rayless trees. Our first goal is to prove the following statement. Proposition 1.2 (known since the 1980s). Suppose is an infinite rayless tree with one distinguished vertex, called its root. If there exists at … Continue reading
Posted in Structure theory
Leave a comment