Metamath Proof Explorer


Theorem crctcshwlkn0lem2

Description: Lemma for crctcshwlkn0 . (Contributed by AV, 12-Mar-2021)

Ref Expression
Hypotheses crctcshwlkn0lem.s φS1..^N
crctcshwlkn0lem.q Q=x0NifxNSPx+SPx+S-N
Assertion crctcshwlkn0lem2 φJ0NSQJ=PJ+S

Proof

Step Hyp Ref Expression
1 crctcshwlkn0lem.s φS1..^N
2 crctcshwlkn0lem.q Q=x0NifxNSPx+SPx+S-N
3 breq1 x=JxNSJNS
4 fvoveq1 x=JPx+S=PJ+S
5 oveq1 x=Jx+S=J+S
6 5 fvoveq1d x=JPx+S-N=PJ+S-N
7 3 4 6 ifbieq12d x=JifxNSPx+SPx+S-N=ifJNSPJ+SPJ+S-N
8 fzo0ss1 1..^N0..^N
9 8 sseli S1..^NS0..^N
10 elfzoel2 S0..^NN
11 elfzonn0 S0..^NS0
12 eluzmn NS0NNS
13 10 11 12 syl2anc S0..^NNNS
14 fzss2 NNS0NS0N
15 13 14 syl S0..^N0NS0N
16 15 sseld S0..^NJ0NSJ0N
17 1 9 16 3syl φJ0NSJ0N
18 17 imp φJ0NSJ0N
19 fvex PJ+SV
20 fvex PJ+S-NV
21 19 20 ifex ifJNSPJ+SPJ+S-NV
22 21 a1i φJ0NSifJNSPJ+SPJ+S-NV
23 2 7 18 22 fvmptd3 φJ0NSQJ=ifJNSPJ+SPJ+S-N
24 elfzle2 J0NSJNS
25 24 adantl φJ0NSJNS
26 25 iftrued φJ0NSifJNSPJ+SPJ+S-N=PJ+S
27 23 26 eqtrd φJ0NSQJ=PJ+S