Description: If the domain of a function is a set, the function is a set. (Contributed by Glauco Siliprandi, 23-Oct-2021)
Ref | Expression | ||
---|---|---|---|
Hypotheses | fnexd.1 | |
|
fnexd.2 | |
||
Assertion | fnexd | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fnexd.1 | |
|
2 | fnexd.2 | |
|
3 | fnex | |
|
4 | 1 2 3 | syl2anc | |