Description: Define the limit ordinal
predicate, which is true for an ordinal that has
the empty set as an element and is not a successor (i.e. that is the union
of itself). Our definition combines the definition of Lim of
[BellMachover] p. 471 and Exercise 1
of [TakeutiZaring] p. 42, and then
changes to (which would be equivalent given the
law of the excluded middle, but which is not for us). (Contributed by Jim
Kingdon, 11-Nov-2018.) Use its alias dflim2 4127 instead for naming
consistency with set.mm. (New usage is
discouraged.) |