📖 Read pages i-20 the front matter and Introduction of Abstract and Concrete Categories: The Joy of Cats by Jirí Adámek, Horst Herrlich, George E. Strecker​

Some initial discussion of sets, classes, and conglomerates to keep us out of trouble with some of the potential foundational issues that can be found in set theory.

Highlights, Quotes, Annotations, & Marginalia

completions of partially orderedsets and of metric spaces,ˇCech-Stone compactifications of topological spaces, sym-metrizations of relations, abelianizations of groups, Bohr compactifications of topo-logical groups, minimalizations of reachable acceptors, etc. ❧

The tough part of category theory is lists of things like this right up front which will tend to scare off almost any reader but those who are working on Ph.D.s in mathematics…
November 30, 2018 at 09:29PM

Motivation ❧

I really wish more math textbooks had motivation sections like this one does.
November 30, 2018 at 09:35PM

Therefore we advise the beginner to skip from here, go directly to§3, and return to this section only when the need arises. ❧

They’ve buried the lede here apparently.
November 30, 2018 at 10:15PM

Kuratowski definition of an ordered pair ❧

I don’t think I’ve ever seen the specific name Kuratowski attached to this.
November 30, 2018 at 10:31PM