Metamath Proof Explorer


Theorem fargshiftfva

Description: The values of a shifted function correspond to the value of the original function. (Contributed by Alexander van der Vekens, 24-Nov-2017)

Ref Expression
Hypothesis fargshift.g G=x0..^FFx+1
Assertion fargshiftfva N0F:1NdomEk1NEFk=k/xPl0..^NEGl=l+1/xP

Proof

Step Hyp Ref Expression
1 fargshift.g G=x0..^FFx+1
2 fz0add1fz1 N0l0..^Nl+11N
3 simpl l+11NN0l0..^Nl+11N
4 3 adantr l+11NN0l0..^NF:1NdomEl+11N
5 2fveq3 k=l+1EFk=EFl+1
6 csbeq1 k=l+1k/xP=l+1/xP
7 5 6 eqeq12d k=l+1EFk=k/xPEFl+1=l+1/xP
8 7 adantl l+11NN0l0..^NF:1NdomEk=l+1EFk=k/xPEFl+1=l+1/xP
9 simpl N0l0..^NN0
10 9 adantl l+11NN0l0..^NN0
11 10 anim1i l+11NN0l0..^NF:1NdomEN0F:1NdomE
12 11 adantr l+11NN0l0..^NF:1NdomEk=l+1N0F:1NdomE
13 simpr N0l0..^Nl0..^N
14 13 ad3antlr l+11NN0l0..^NF:1NdomEk=l+1l0..^N
15 1 fargshiftfv N0F:1NdomEl0..^NGl=Fl+1
16 15 imp N0F:1NdomEl0..^NGl=Fl+1
17 16 eqcomd N0F:1NdomEl0..^NFl+1=Gl
18 12 14 17 syl2anc l+11NN0l0..^NF:1NdomEk=l+1Fl+1=Gl
19 18 fveqeq2d l+11NN0l0..^NF:1NdomEk=l+1EFl+1=l+1/xPEGl=l+1/xP
20 8 19 bitrd l+11NN0l0..^NF:1NdomEk=l+1EFk=k/xPEGl=l+1/xP
21 4 20 rspcdv l+11NN0l0..^NF:1NdomEk1NEFk=k/xPEGl=l+1/xP
22 21 ex l+11NN0l0..^NF:1NdomEk1NEFk=k/xPEGl=l+1/xP
23 22 com23 l+11NN0l0..^Nk1NEFk=k/xPF:1NdomEEGl=l+1/xP
24 2 23 mpancom N0l0..^Nk1NEFk=k/xPF:1NdomEEGl=l+1/xP
25 24 ex N0l0..^Nk1NEFk=k/xPF:1NdomEEGl=l+1/xP
26 25 com24 N0F:1NdomEk1NEFk=k/xPl0..^NEGl=l+1/xP
27 26 imp31 N0F:1NdomEk1NEFk=k/xPl0..^NEGl=l+1/xP
28 27 ralrimiv N0F:1NdomEk1NEFk=k/xPl0..^NEGl=l+1/xP
29 28 ex N0F:1NdomEk1NEFk=k/xPl0..^NEGl=l+1/xP