Description: Value of the open interval function. (Contributed by NM, 6-Feb-2007) (Revised by Mario Carneiro, 3-Nov-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | iooval2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | iooval | |
|
2 | elioore | |
|
3 | 2 | ssriv | |
4 | 1 3 | eqsstrrdi | |
5 | df-ss | |
|
6 | 4 5 | sylib | |
7 | inrab2 | |
|
8 | ressxr | |
|
9 | sseqin2 | |
|
10 | 8 9 | mpbi | |
11 | 10 | rabeqi | |
12 | 7 11 | eqtri | |
13 | 6 12 | eqtr3di | |
14 | 1 13 | eqtrd | |