Description: Base set of the inclusion poset. (Contributed by Stefan O'Rear, 30-Jan-2015) (Revised by Mario Carneiro, 25-Oct-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | ipoval.i | |
|
Assertion | ipobas | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ipoval.i | |
|
2 | ipostr | |
|
3 | baseid | |
|
4 | snsspr1 | |
|
5 | ssun1 | |
|
6 | 4 5 | sstri | |
7 | 2 3 6 | strfv | |
8 | eqid | |
|
9 | 1 8 | ipoval | |
10 | 9 | fveq2d | |
11 | 7 10 | eqtr4d | |