Description: A function with bounded domain and range is a set. This version of fex is proven without the Axiom of Replacement ax-rep , but depends on ax-un , which is not required for the proof of fex . (Contributed by Mario Carneiro, 24-Jun-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | fex2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xpexg | |
|
2 | 1 | 3adant1 | |
3 | fssxp | |
|
4 | 3 | 3ad2ant1 | |
5 | 2 4 | ssexd | |