Description: Lemma for bj-ax6e . (Contributed by BJ, 22-Dec-2020) (Proof modification is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-ax6elem2 | |- ( A. x y = z -> E. x x = y ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ax6ev | |- E. x x = z |
|
2 | equeucl | |- ( x = z -> ( y = z -> x = y ) ) |
|
3 | 1 2 | eximii | |- E. x ( y = z -> x = y ) |
4 | 3 | 19.35i | |- ( A. x y = z -> E. x x = y ) |