Description: A singleton index picks out an instance of an indexed union's argument. (Contributed by Glauco Siliprandi, 17-Aug-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | iunxsnf.1 | |
|
iunxsnf.2 | |
||
iunxsnf.3 | |
||
Assertion | iunxsnf | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | iunxsnf.1 | |
|
2 | iunxsnf.2 | |
|
3 | iunxsnf.3 | |
|
4 | 1 3 | iunxsngf | |
5 | 2 4 | ax-mp | |