Description: The domain of a set is a set. Corollary 6.8(2) of TakeutiZaring p. 26. (Contributed by NM, 7-Jul-2008)
Ref | Expression | ||
---|---|---|---|
Hypothesis | dmex.1 | |
|
Assertion | dmex | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dmex.1 | |
|
2 | dmexg | |
|
3 | 1 2 | ax-mp | |