Description: Under subset ordering, the intersection of a class abstraction is less than or equal to any of its members. (Contributed by NM, 3-Jul-2005)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | intmin3.2 | |- ( x = A -> ( ph <-> ps ) ) | |
| intmin3.3 | |- ps | ||
| Assertion | intmin3 | |- ( A e. V -> |^| { x | ph } C_ A ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | intmin3.2 | |- ( x = A -> ( ph <-> ps ) ) | |
| 2 | intmin3.3 | |- ps | |
| 3 | 1 | elabg |  |-  ( A e. V -> ( A e. { x | ph } <-> ps ) ) | 
| 4 | 2 3 | mpbiri |  |-  ( A e. V -> A e. { x | ph } ) | 
| 5 | intss1 |  |-  ( A e. { x | ph } -> |^| { x | ph } C_ A ) | |
| 6 | 4 5 | syl |  |-  ( A e. V -> |^| { x | ph } C_ A ) |