for PETSc v3.17.0

C codes (Chapters 1--12) were tested with PETSc 3.17.0 (main branch, commit 24d29bbf)

Python codes (Chapters 13--14) were tested with Firedrake commit bc795025

Gmsh version 4.9.3 (and 4.9.0)

Test machine: ed-galago ubuntu 20.04