Description: Value of join function for a poset-type structure. (Contributed by NM, 12-Sep-2011) (Revised by NM, 9-Sep-2018)
Ref | Expression | ||
---|---|---|---|
Hypotheses | joinfval.u | |
|
joinfval.j | |
||
Assertion | joinfval2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | joinfval.u | |
|
2 | joinfval.j | |
|
3 | 1 2 | joinfval | |
4 | 1 | lubfun | |
5 | funbrfv2b | |
|
6 | 4 5 | ax-mp | |
7 | eqcom | |
|
8 | 7 | anbi2i | |
9 | 6 8 | bitri | |
10 | 9 | oprabbii | |
11 | 3 10 | eqtrdi | |