+> Topics: Mutation and hyper-synonymy (no notes); [[Abortable list traversals|/topics/week12_abortable_traversals]]; [[List and tree zippers|/topics/week12_list_and_tree_zippers]]; Homework <!-- [[Homework|exercises/assignment12]] -->
+
+> For amusement/tangential edification: [xkcd on code quality](https://xkcd.com/1513/); [turning a sphere inside out](https://www.youtube.com/watch?v=-6g3ZcmjJ7k)