Yeah, it doesn’t (obviously) follow. See the appendix on equality. It made the proof simpler and I thought most readers would not find it objectionable, but if you have a suggestion for an alternate simple proof I would love to hear it!
Yeah, it doesn’t (obviously) follow. See the appendix on equality. It made the proof simpler and I thought most readers would not find it objectionable, but if you have a suggestion for an alternate simple proof I would love to hear it!