| Step | Hyp | Ref
 | Expression | 
| 1 |   | eqid 2196 | 
. . . 4
⊢
(ℤ≥‘𝑀) = (ℤ≥‘𝑀) | 
| 2 |   | seq3shft.m | 
. . . 4
⊢ (𝜑 → 𝑀 ∈ ℤ) | 
| 3 |   | seq3shft.ex | 
. . . . . . 7
⊢ (𝜑 → 𝐹 ∈ 𝑉) | 
| 4 | 3 | adantr 276 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝐹 ∈ 𝑉) | 
| 5 |   | seq3shft.n | 
. . . . . . . 8
⊢ (𝜑 → 𝑁 ∈ ℤ) | 
| 6 | 5 | zcnd 9449 | 
. . . . . . 7
⊢ (𝜑 → 𝑁 ∈ ℂ) | 
| 7 | 6 | adantr 276 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑁 ∈ ℂ) | 
| 8 |   | eluzelz 9610 | 
. . . . . . . 8
⊢ (𝑥 ∈
(ℤ≥‘𝑀) → 𝑥 ∈ ℤ) | 
| 9 | 8 | adantl 277 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑥 ∈ ℤ) | 
| 10 | 9 | zcnd 9449 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑥 ∈ ℂ) | 
| 11 |   | shftvalg 11001 | 
. . . . . 6
⊢ ((𝐹 ∈ 𝑉 ∧ 𝑁 ∈ ℂ ∧ 𝑥 ∈ ℂ) → ((𝐹 shift 𝑁)‘𝑥) = (𝐹‘(𝑥 − 𝑁))) | 
| 12 | 4, 7, 10, 11 | syl3anc 1249 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → ((𝐹 shift 𝑁)‘𝑥) = (𝐹‘(𝑥 − 𝑁))) | 
| 13 |   | fveq2 5558 | 
. . . . . . 7
⊢ (𝑎 = (𝑥 − 𝑁) → (𝐹‘𝑎) = (𝐹‘(𝑥 − 𝑁))) | 
| 14 | 13 | eleq1d 2265 | 
. . . . . 6
⊢ (𝑎 = (𝑥 − 𝑁) → ((𝐹‘𝑎) ∈ 𝑆 ↔ (𝐹‘(𝑥 − 𝑁)) ∈ 𝑆)) | 
| 15 |   | seq3shft.fn | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘(𝑀 − 𝑁))) → (𝐹‘𝑥) ∈ 𝑆) | 
| 16 | 15 | ralrimiva 2570 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑥 ∈ (ℤ≥‘(𝑀 − 𝑁))(𝐹‘𝑥) ∈ 𝑆) | 
| 17 |   | fveq2 5558 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑎 → (𝐹‘𝑥) = (𝐹‘𝑎)) | 
| 18 | 17 | eleq1d 2265 | 
. . . . . . . . 9
⊢ (𝑥 = 𝑎 → ((𝐹‘𝑥) ∈ 𝑆 ↔ (𝐹‘𝑎) ∈ 𝑆)) | 
| 19 | 18 | cbvralv 2729 | 
. . . . . . . 8
⊢
(∀𝑥 ∈
(ℤ≥‘(𝑀 − 𝑁))(𝐹‘𝑥) ∈ 𝑆 ↔ ∀𝑎 ∈ (ℤ≥‘(𝑀 − 𝑁))(𝐹‘𝑎) ∈ 𝑆) | 
| 20 | 16, 19 | sylib 122 | 
. . . . . . 7
⊢ (𝜑 → ∀𝑎 ∈ (ℤ≥‘(𝑀 − 𝑁))(𝐹‘𝑎) ∈ 𝑆) | 
| 21 | 20 | adantr 276 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → ∀𝑎 ∈
(ℤ≥‘(𝑀 − 𝑁))(𝐹‘𝑎) ∈ 𝑆) | 
| 22 | 2, 5 | zsubcld 9453 | 
. . . . . . . 8
⊢ (𝜑 → (𝑀 − 𝑁) ∈ ℤ) | 
| 23 | 22 | adantr 276 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝑀 − 𝑁) ∈ ℤ) | 
| 24 | 5 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑁 ∈ ℤ) | 
| 25 | 9, 24 | zsubcld 9453 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝑥 − 𝑁) ∈ ℤ) | 
| 26 | 2 | zred 9448 | 
. . . . . . . . 9
⊢ (𝜑 → 𝑀 ∈ ℝ) | 
| 27 | 26 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑀 ∈ ℝ) | 
| 28 | 9 | zred 9448 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑥 ∈ ℝ) | 
| 29 | 24 | zred 9448 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑁 ∈ ℝ) | 
| 30 |   | eluzle 9613 | 
. . . . . . . . 9
⊢ (𝑥 ∈
(ℤ≥‘𝑀) → 𝑀 ≤ 𝑥) | 
| 31 | 30 | adantl 277 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑀 ≤ 𝑥) | 
| 32 | 27, 28, 29, 31 | lesub1dd 8588 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝑀 − 𝑁) ≤ (𝑥 − 𝑁)) | 
| 33 |   | eluz2 9607 | 
. . . . . . 7
⊢ ((𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁)) ↔ ((𝑀 − 𝑁) ∈ ℤ ∧ (𝑥 − 𝑁) ∈ ℤ ∧ (𝑀 − 𝑁) ≤ (𝑥 − 𝑁))) | 
| 34 | 23, 25, 32, 33 | syl3anbrc 1183 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))) | 
| 35 | 14, 21, 34 | rspcdva 2873 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐹‘(𝑥 − 𝑁)) ∈ 𝑆) | 
| 36 | 12, 35 | eqeltrd 2273 | 
. . . 4
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → ((𝐹 shift 𝑁)‘𝑥) ∈ 𝑆) | 
| 37 |   | seq3shft.pl | 
. . . 4
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 38 | 1, 2, 36, 37 | seqf 10556 | 
. . 3
⊢ (𝜑 → seq𝑀( + , (𝐹 shift 𝑁)):(ℤ≥‘𝑀)⟶𝑆) | 
| 39 | 38 | ffnd 5408 | 
. 2
⊢ (𝜑 → seq𝑀( + , (𝐹 shift 𝑁)) Fn (ℤ≥‘𝑀)) | 
| 40 |   | eqid 2196 | 
. . . . . 6
⊢
(ℤ≥‘(𝑀 − 𝑁)) = (ℤ≥‘(𝑀 − 𝑁)) | 
| 41 | 40, 22, 15, 37 | seqf 10556 | 
. . . . 5
⊢ (𝜑 → seq(𝑀 − 𝑁)( + , 𝐹):(ℤ≥‘(𝑀 − 𝑁))⟶𝑆) | 
| 42 | 41 | ffnd 5408 | 
. . . 4
⊢ (𝜑 → seq(𝑀 − 𝑁)( + , 𝐹) Fn (ℤ≥‘(𝑀 − 𝑁))) | 
| 43 |   | seqex 10541 | 
. . . . 5
⊢ seq(𝑀 − 𝑁)( + , 𝐹) ∈ V | 
| 44 | 43 | shftfn 10989 | 
. . . 4
⊢
((seq(𝑀 −
𝑁)( + , 𝐹) Fn (ℤ≥‘(𝑀 − 𝑁)) ∧ 𝑁 ∈ ℂ) → (seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁) Fn {𝑥 ∈ ℂ ∣ (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))}) | 
| 45 | 42, 6, 44 | syl2anc 411 | 
. . 3
⊢ (𝜑 → (seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁) Fn {𝑥 ∈ ℂ ∣ (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))}) | 
| 46 |   | shftuz 10982 | 
. . . . . 6
⊢ ((𝑁 ∈ ℤ ∧ (𝑀 − 𝑁) ∈ ℤ) → {𝑥 ∈ ℂ ∣ (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))} = (ℤ≥‘((𝑀 − 𝑁) + 𝑁))) | 
| 47 | 5, 22, 46 | syl2anc 411 | 
. . . . 5
⊢ (𝜑 → {𝑥 ∈ ℂ ∣ (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))} = (ℤ≥‘((𝑀 − 𝑁) + 𝑁))) | 
| 48 | 2 | zcnd 9449 | 
. . . . . . 7
⊢ (𝜑 → 𝑀 ∈ ℂ) | 
| 49 | 48, 6 | npcand 8341 | 
. . . . . 6
⊢ (𝜑 → ((𝑀 − 𝑁) + 𝑁) = 𝑀) | 
| 50 | 49 | fveq2d 5562 | 
. . . . 5
⊢ (𝜑 →
(ℤ≥‘((𝑀 − 𝑁) + 𝑁)) = (ℤ≥‘𝑀)) | 
| 51 | 47, 50 | eqtrd 2229 | 
. . . 4
⊢ (𝜑 → {𝑥 ∈ ℂ ∣ (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))} = (ℤ≥‘𝑀)) | 
| 52 | 51 | fneq2d 5349 | 
. . 3
⊢ (𝜑 → ((seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁) Fn {𝑥 ∈ ℂ ∣ (𝑥 − 𝑁) ∈
(ℤ≥‘(𝑀 − 𝑁))} ↔ (seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁) Fn (ℤ≥‘𝑀))) | 
| 53 | 45, 52 | mpbid 147 | 
. 2
⊢ (𝜑 → (seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁) Fn (ℤ≥‘𝑀)) | 
| 54 | 48, 6 | negsubd 8343 | 
. . . . . 6
⊢ (𝜑 → (𝑀 + -𝑁) = (𝑀 − 𝑁)) | 
| 55 | 54 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → (𝑀 + -𝑁) = (𝑀 − 𝑁)) | 
| 56 | 55 | seqeq1d 10545 | 
. . . 4
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → seq(𝑀 + -𝑁)( + , 𝐹) = seq(𝑀 − 𝑁)( + , 𝐹)) | 
| 57 |   | eluzelcn 9612 | 
. . . . . 6
⊢ (𝑧 ∈
(ℤ≥‘𝑀) → 𝑧 ∈ ℂ) | 
| 58 | 57 | adantl 277 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → 𝑧 ∈ ℂ) | 
| 59 | 6 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → 𝑁 ∈ ℂ) | 
| 60 | 58, 59 | negsubd 8343 | 
. . . 4
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → (𝑧 + -𝑁) = (𝑧 − 𝑁)) | 
| 61 | 56, 60 | fveq12d 5565 | 
. . 3
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → (seq(𝑀 + -𝑁)( + , 𝐹)‘(𝑧 + -𝑁)) = (seq(𝑀 − 𝑁)( + , 𝐹)‘(𝑧 − 𝑁))) | 
| 62 |   | simpr 110 | 
. . . 4
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → 𝑧 ∈ (ℤ≥‘𝑀)) | 
| 63 | 5 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → 𝑁 ∈ ℤ) | 
| 64 | 63 | znegcld 9450 | 
. . . 4
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → -𝑁 ∈ ℤ) | 
| 65 | 3 | ad2antrr 488 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → 𝐹 ∈ 𝑉) | 
| 66 | 59 | adantr 276 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → 𝑁 ∈ ℂ) | 
| 67 |   | elfzelz 10100 | 
. . . . . . . 8
⊢ (𝑦 ∈ (𝑀...𝑧) → 𝑦 ∈ ℤ) | 
| 68 | 67 | adantl 277 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → 𝑦 ∈ ℤ) | 
| 69 | 68 | zcnd 9449 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → 𝑦 ∈ ℂ) | 
| 70 |   | shftvalg 11001 | 
. . . . . 6
⊢ ((𝐹 ∈ 𝑉 ∧ 𝑁 ∈ ℂ ∧ 𝑦 ∈ ℂ) → ((𝐹 shift 𝑁)‘𝑦) = (𝐹‘(𝑦 − 𝑁))) | 
| 71 | 65, 66, 69, 70 | syl3anc 1249 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → ((𝐹 shift 𝑁)‘𝑦) = (𝐹‘(𝑦 − 𝑁))) | 
| 72 | 69, 66 | negsubd 8343 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → (𝑦 + -𝑁) = (𝑦 − 𝑁)) | 
| 73 | 72 | fveq2d 5562 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → (𝐹‘(𝑦 + -𝑁)) = (𝐹‘(𝑦 − 𝑁))) | 
| 74 | 71, 73 | eqtr4d 2232 | 
. . . 4
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑦 ∈ (𝑀...𝑧)) → ((𝐹 shift 𝑁)‘𝑦) = (𝐹‘(𝑦 + -𝑁))) | 
| 75 | 36 | adantlr 477 | 
. . . 4
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → ((𝐹 shift 𝑁)‘𝑥) ∈ 𝑆) | 
| 76 |   | simpll 527 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁))) → 𝜑) | 
| 77 |   | simpr 110 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁))) → 𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁))) | 
| 78 | 54 | fveq2d 5562 | 
. . . . . . . 8
⊢ (𝜑 →
(ℤ≥‘(𝑀 + -𝑁)) = (ℤ≥‘(𝑀 − 𝑁))) | 
| 79 | 78 | eleq2d 2266 | 
. . . . . . 7
⊢ (𝜑 → (𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁)) ↔ 𝑥 ∈ (ℤ≥‘(𝑀 − 𝑁)))) | 
| 80 | 79 | ad2antrr 488 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁))) → (𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁)) ↔ 𝑥 ∈ (ℤ≥‘(𝑀 − 𝑁)))) | 
| 81 | 77, 80 | mpbid 147 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁))) → 𝑥 ∈ (ℤ≥‘(𝑀 − 𝑁))) | 
| 82 | 76, 81, 15 | syl2anc 411 | 
. . . 4
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ∈ (ℤ≥‘(𝑀 + -𝑁))) → (𝐹‘𝑥) ∈ 𝑆) | 
| 83 | 37 | adantlr 477 | 
. . . 4
⊢ (((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 84 | 62, 64, 74, 75, 82, 83 | seq3shft2 10573 | 
. . 3
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → (seq𝑀( + , (𝐹 shift 𝑁))‘𝑧) = (seq(𝑀 + -𝑁)( + , 𝐹)‘(𝑧 + -𝑁))) | 
| 85 |   | shftvalg 11001 | 
. . . 4
⊢
((seq(𝑀 −
𝑁)( + , 𝐹) ∈ V ∧ 𝑁 ∈ ℂ ∧ 𝑧 ∈ ℂ) → ((seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁)‘𝑧) = (seq(𝑀 − 𝑁)( + , 𝐹)‘(𝑧 − 𝑁))) | 
| 86 | 43, 59, 58, 85 | mp3an2i 1353 | 
. . 3
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → ((seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁)‘𝑧) = (seq(𝑀 − 𝑁)( + , 𝐹)‘(𝑧 − 𝑁))) | 
| 87 | 61, 84, 86 | 3eqtr4d 2239 | 
. 2
⊢ ((𝜑 ∧ 𝑧 ∈ (ℤ≥‘𝑀)) → (seq𝑀( + , (𝐹 shift 𝑁))‘𝑧) = ((seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁)‘𝑧)) | 
| 88 | 39, 53, 87 | eqfnfvd 5662 | 
1
⊢ (𝜑 → seq𝑀( + , (𝐹 shift 𝑁)) = (seq(𝑀 − 𝑁)( + , 𝐹) shift 𝑁)) |