Description: Absorption of an existential quantifier of a double existential quantifier of non-distinct variables. e2ebind is derived from e2ebindVD . (Contributed by Alan Sare, 27-Nov-2014) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | e2ebind |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | biidd | ||
2 | 1 | drex1 | |
3 | 2 | drex2 | |
4 | excom | ||
5 | 3 4 | syl6bb | |
6 | nfe1 | ||
7 | 6 | 19.9 | |
8 | 5 7 | bitr3di | |
9 | 8 | aecoms |