Description: Membership in a class abstraction, using implicit substitution. (Contributed by NM, 17-Oct-2012)
Ref | Expression | ||
---|---|---|---|
Hypotheses | elab4g.1 | |- ( x = A -> ( ph <-> ps ) ) |
|
elab4g.2 | |- B = { x | ph } |
||
Assertion | elab4g | |- ( A e. B <-> ( A e. _V /\ ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elab4g.1 | |- ( x = A -> ( ph <-> ps ) ) |
|
2 | elab4g.2 | |- B = { x | ph } |
|
3 | elex | |- ( A e. B -> A e. _V ) |
|
4 | 1 2 | elab2g | |- ( A e. _V -> ( A e. B <-> ps ) ) |
5 | 3 4 | biadanii | |- ( A e. B <-> ( A e. _V /\ ps ) ) |