Description: Reversal of scanning order inside of a universal quantification restricted to a finite set of sequential integers. (Contributed by NM, 25-Nov-2005)
Ref | Expression | ||
---|---|---|---|
Assertion | fzrevral | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpr | |
|
2 | elfzelz | |
|
3 | fzrev | |
|
4 | 3 | anassrs | |
5 | 2 4 | sylan2 | |
6 | 1 5 | mpbid | |
7 | rspsbc | |
|
8 | 6 7 | syl | |
9 | 8 | ex3 | |
10 | 9 | com23 | |
11 | 10 | ralrimdv | |
12 | nfv | |
|
13 | nfcv | |
|
14 | nfsbc1v | |
|
15 | 13 14 | nfralw | |
16 | fzrev2i | |
|
17 | oveq2 | |
|
18 | 17 | sbceq1d | |
19 | 18 | rspcv | |
20 | 16 19 | syl | |
21 | zcn | |
|
22 | elfzelz | |
|
23 | 22 | zcnd | |
24 | nncan | |
|
25 | 21 23 24 | syl2an | |
26 | 25 | eqcomd | |
27 | sbceq1a | |
|
28 | 26 27 | syl | |
29 | 20 28 | sylibrd | |
30 | 29 | ex | |
31 | 30 | com23 | |
32 | 12 15 31 | ralrimd | |
33 | 32 | 3ad2ant3 | |
34 | 11 33 | impbid | |