Description: Plus infinity exists. (Contributed by David A. Wheeler, 8-Dec-2018) (Revised by Steven Nguyen, 7-Dec-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | pnfex | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-pnf | |
|
2 | cnex | |
|
3 | 2 | uniex | |
4 | 3 | pwex | |
5 | 1 4 | eqeltri | |