For a broader discussion about natural deduction in set.mm (and iset.mm!, see: https://us.metamath.org/mpeuni/mmnatded.html
That in turn links to: https://us.metamath.org/mpeuni/natded.html --- David A. Wheeler -- You received this message because you are subscribed to the Google Groups "Metamath" group. To unsubscribe from this group and stop receiving emails from it, send an email to metamath+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/metamath/D9B69169-C136-4D33-9266-30D19E65752A%40dwheeler.com.
