Description: Utility theorem: index-independent form of df-itv . (Contributed by Thierry Arnoux, 24-Aug-2017)
Ref | Expression | ||
---|---|---|---|
Assertion | itvid | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-itv | |
|
2 | 1nn0 | |
|
3 | 6nn | |
|
4 | 2 3 | decnncl | |
5 | 1 4 | ndxid | |