Metamath Proof Explorer


Theorem ovolficc

Description: Unpack the interval covering property using closed intervals. (Contributed by Mario Carneiro, 16-Mar-2014)

Ref Expression
Assertion ovolficc AF:2Aran.FzAn1stFnzz2ndFn

Proof

Step Hyp Ref Expression
1 iccf .:*×*𝒫*
2 inss2 22
3 rexpssxrxp 2*×*
4 2 3 sstri 2*×*
5 fss F:22*×*F:*×*
6 4 5 mpan2 F:2F:*×*
7 fco .:*×*𝒫*F:*×*.F:𝒫*
8 1 6 7 sylancr F:2.F:𝒫*
9 ffn .F:𝒫*.FFn
10 fniunfv .FFnn.Fn=ran.F
11 8 9 10 3syl F:2n.Fn=ran.F
12 11 sseq2d F:2An.FnAran.F
13 12 adantl AF:2An.FnAran.F
14 dfss3 An.FnzAzn.Fn
15 ssel2 AzAz
16 eliun zn.Fnnz.Fn
17 simpll zF:2nz
18 fvco3 F:2n.Fn=.Fn
19 ffvelcdm F:2nFn2
20 19 elin2d F:2nFn2
21 1st2nd2 Fn2Fn=1stFn2ndFn
22 20 21 syl F:2nFn=1stFn2ndFn
23 22 fveq2d F:2n.Fn=.1stFn2ndFn
24 df-ov 1stFn2ndFn=.1stFn2ndFn
25 23 24 eqtr4di F:2n.Fn=1stFn2ndFn
26 18 25 eqtrd F:2n.Fn=1stFn2ndFn
27 26 eleq2d F:2nz.Fnz1stFn2ndFn
28 ovolfcl F:2n1stFn2ndFn1stFn2ndFn
29 elicc2 1stFn2ndFnz1stFn2ndFnz1stFnzz2ndFn
30 3anass z1stFnzz2ndFnz1stFnzz2ndFn
31 29 30 bitrdi 1stFn2ndFnz1stFn2ndFnz1stFnzz2ndFn
32 31 3adant3 1stFn2ndFn1stFn2ndFnz1stFn2ndFnz1stFnzz2ndFn
33 28 32 syl F:2nz1stFn2ndFnz1stFnzz2ndFn
34 27 33 bitrd F:2nz.Fnz1stFnzz2ndFn
35 34 adantll zF:2nz.Fnz1stFnzz2ndFn
36 17 35 mpbirand zF:2nz.Fn1stFnzz2ndFn
37 36 rexbidva zF:2nz.Fnn1stFnzz2ndFn
38 16 37 bitrid zF:2zn.Fnn1stFnzz2ndFn
39 15 38 sylan AzAF:2zn.Fnn1stFnzz2ndFn
40 39 an32s AF:2zAzn.Fnn1stFnzz2ndFn
41 40 ralbidva AF:2zAzn.FnzAn1stFnzz2ndFn
42 14 41 bitrid AF:2An.FnzAn1stFnzz2ndFn
43 13 42 bitr3d AF:2Aran.FzAn1stFnzz2ndFn