## Vignettes. Part 2.

Mathematicians working in algebraic graph theory call what mathematicians working in  graph-theory independent sets by the name cocliques, and call complete graphs by the name cliques. Mathematicians working in category theory tend to call those independent sets by the name free graph (on said vertex set), and call complete graphs by the name cofree graph (on its vertex set). So there is sort-of a hazardousness=infelicity, in that  coclique$\equiv$free, and clique$\equiv$cofree, and it would be felicitous for the prefixes co- to co-occur.

(Note that not[ hazardousness $\Rightarrow$ $\neg$  felicity ].)