Description: Formula-building lemma for use with the Distinctor Reduction Theorem. Usage of this theorem is discouraged because it depends on ax-13 . (Contributed by Mario Carneiro, 8-Oct-2016) Avoid ax-11 . (Revised by Wolf Lammen, 10-May-2023) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | drnfc1.1 | ||
Assertion | drnfc1 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | drnfc1.1 | ||
2 | 1 | eleq2d | |
3 | 2 | drnf1 | |
4 | 3 | albidv | |
5 | df-nfc | ||
6 | df-nfc | ||
7 | 4 5 6 | 3bitr4g |