Description: Functionality of a shifted sequence. (Contributed by NM, 19-Aug-2005) (Revised by Mario Carneiro, 5-Nov-2013)
Ref | Expression | ||
---|---|---|---|
Hypothesis | shftfval.1 | |
|
Assertion | shftf | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | shftfval.1 | |
|
2 | ffn | |
|
3 | 1 | shftfn | |
4 | 2 3 | sylan | |
5 | oveq1 | |
|
6 | 5 | eleq1d | |
7 | 6 | elrab | |
8 | simpr | |
|
9 | simpl | |
|
10 | 1 | shftval | |
11 | 8 9 10 | syl2an | |
12 | simpl | |
|
13 | simpr | |
|
14 | ffvelcdm | |
|
15 | 12 13 14 | syl2an | |
16 | 11 15 | eqeltrd | |
17 | 7 16 | sylan2b | |
18 | 17 | ralrimiva | |
19 | ffnfv | |
|
20 | 4 18 19 | sylanbrc | |