Description: A rectangular subset of a rectangular set can be recovered as the relative intersection of single-axis restrictions. (Contributed by Stefan O'Rear, 22-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | boxriin | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simprl | |
|
2 | ssel | |
|
3 | 2 | ral2imi | |
4 | 3 | adantr | |
5 | 4 | impr | |
6 | eleq2 | |
|
7 | eleq2 | |
|
8 | simplr | |
|
9 | ssel2 | |
|
10 | 9 | adantr | |
11 | 6 7 8 10 | ifbothda | |
12 | 11 | ex | |
13 | 12 | ral2imi | |
14 | 13 | adantr | |
15 | 14 | impr | |
16 | 1 15 | jca | |
17 | 16 | ralrimivw | |
18 | 1 5 17 | jca31 | |
19 | simprll | |
|
20 | simpr | |
|
21 | 20 | ralimi | |
22 | ralcom | |
|
23 | iftrue | |
|
24 | 23 | equcoms | |
25 | 24 | eleq2d | |
26 | 25 | rspcva | |
27 | 26 | ralimiaa | |
28 | 22 27 | sylbi | |
29 | 21 28 | syl | |
30 | 29 | ad2antll | |
31 | 19 30 | jca | |
32 | 18 31 | impbida | |
33 | vex | |
|
34 | 33 | elixp | |
35 | elin | |
|
36 | 33 | elixp | |
37 | eliin | |
|
38 | 37 | elv | |
39 | 33 | elixp | |
40 | 39 | ralbii | |
41 | 38 40 | bitri | |
42 | 36 41 | anbi12i | |
43 | 35 42 | bitri | |
44 | 32 34 43 | 3bitr4g | |
45 | 44 | eqrdv | |