Description: A rearrangement of intersection. (Contributed by NM, 27-Aug-2012)
Ref | Expression | ||
---|---|---|---|
Assertion | in31 | |- ( ( A i^i B ) i^i C ) = ( ( C i^i B ) i^i A ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | in12 | |- ( C i^i ( A i^i B ) ) = ( A i^i ( C i^i B ) ) |
|
2 | incom | |- ( ( A i^i B ) i^i C ) = ( C i^i ( A i^i B ) ) |
|
3 | incom | |- ( ( C i^i B ) i^i A ) = ( A i^i ( C i^i B ) ) |
|
4 | 1 2 3 | 3eqtr4i | |- ( ( A i^i B ) i^i C ) = ( ( C i^i B ) i^i A ) |