Flip ordinal multiplication’s arguments.

The argument that is recursed on is the second argument.  This gives

  2 × ω = ω ≠ ω + ω = ω × 2

This brings my notation in line with convention, as determined by
looking at

  Johnstone, “Notes on logic and set theory”
  Mendelson, “Intro. to mathematical logic”
  Potter, “Set theory and its philosophy”

and even Wikipedia.