Metamath Proof Explorer


Theorem lgsval4a

Description: Same as lgsval4 for positive N . (Contributed by Mario Carneiro, 4-Feb-2015)

Ref Expression
Hypothesis lgsval4.1 F = n if n A / L n n pCnt N 1
Assertion lgsval4a A N A / L N = seq 1 × F N

Proof

Step Hyp Ref Expression
1 lgsval4.1 F = n if n A / L n n pCnt N 1
2 simpl A N A
3 nnz N N
4 3 adantl A N N
5 nnne0 N N 0
6 5 adantl A N N 0
7 1 lgsval4 A N N 0 A / L N = if N < 0 A < 0 1 1 seq 1 × F N
8 2 4 6 7 syl3anc A N A / L N = if N < 0 A < 0 1 1 seq 1 × F N
9 nngt0 N 0 < N
10 9 adantl A N 0 < N
11 0re 0
12 nnre N N
13 12 adantl A N N
14 ltnsym 0 N 0 < N ¬ N < 0
15 11 13 14 sylancr A N 0 < N ¬ N < 0
16 10 15 mpd A N ¬ N < 0
17 16 intnanrd A N ¬ N < 0 A < 0
18 17 iffalsed A N if N < 0 A < 0 1 1 = 1
19 nnnn0 N N 0
20 19 adantl A N N 0
21 20 nn0ge0d A N 0 N
22 13 21 absidd A N N = N
23 22 fveq2d A N seq 1 × F N = seq 1 × F N
24 18 23 oveq12d A N if N < 0 A < 0 1 1 seq 1 × F N = 1 seq 1 × F N
25 simpr A N N
26 nnuz = 1
27 25 26 eleqtrdi A N N 1
28 1 lgsfcl3 A N N 0 F :
29 2 4 6 28 syl3anc A N F :
30 elfznn x 1 N x
31 ffvelrn F : x F x
32 29 30 31 syl2an A N x 1 N F x
33 zmulcl x y x y
34 33 adantl A N x y x y
35 27 32 34 seqcl A N seq 1 × F N
36 35 zcnd A N seq 1 × F N
37 36 mulid2d A N 1 seq 1 × F N = seq 1 × F N
38 8 24 37 3eqtrd A N A / L N = seq 1 × F N