Maybe Wikipedia (https://en.wikipedia.org/wiki/Infinity#Calculus) gives some hints: * In real analysis <https://en.wikipedia.org/wiki/Real_analysis>, the symbol , called "infinity", is used to denote an unbounded limit <https://en.wikipedia.org/wiki/Limit_of_a_function>. The notation x --> +oo means that x increases without bound, and x --> -oo means that x decreases without bound. * In complex analysis <https://en.wikipedia.org/wiki/Complex_analysis> the symbol oo, called "infinity", denotes an unsigned infinite limit <https://en.wikipedia.org/wiki/Limit_(mathematics)>. x --> oo means that the magnitude |x| of x grows beyond any assigned value.
Especially in the real case, we have the definition of superior limit limsup which can take the values -oo and +oo, see ~ limsupcl . As far as I know, there is nothing in set.mm corresponding to the complex case. -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/metamath/543d0c10-f9d0-4394-8d81-98e216cc0269n%40googlegroups.com.
