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Theorem fldext2chn 34127
Description: In a non-empty chain 𝑇 of quadratic field extensions, the degree of the final extension is always a power of two. (Contributed by Thierry Arnoux, 19-Oct-2025.)
Hypotheses
Ref Expression
fldext2chn.e 𝐸 = (𝑊s 𝑒)
fldext2chn.f 𝐹 = (𝑊s 𝑓)
fldext2chn.l < = {⟨𝑓, 𝑒⟩ ∣ (𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2)}
fldext2chn.t (𝜑𝑇 ∈ ( < Chain (SubDRing‘𝑊)))
fldext2chn.w (𝜑𝑊 ∈ Field)
fldext2chn.1 (𝜑 → (𝑊s (𝑇‘0)) = 𝑄)
fldext2chn.2 (𝜑 → (𝑊s (lastS‘𝑇)) = 𝐿)
fldext2chn.3 (𝜑 → 0 < (♯‘𝑇))
Assertion
Ref Expression
fldext2chn (𝜑 → (𝐿/FldExt𝑄 ∧ ∃𝑛 ∈ ℕ0 (𝐿[:]𝑄) = (2↑𝑛)))
Distinct variable groups:   𝑇,𝑛   𝑛,𝑊   𝑒,𝑊,𝑓   𝜑,𝑛
Allowed substitution hints:   𝜑(𝑒, 𝑓)   𝑄(𝑒, 𝑓, 𝑛)   < (𝑒, 𝑓, 𝑛)   𝑇(𝑒, 𝑓)   𝐸(𝑒, 𝑓, 𝑛)   𝐹(𝑒, 𝑓, 𝑛)   𝐿(𝑒, 𝑓, 𝑛)

Proof of Theorem fldext2chn
Dummy variables 𝑐 𝑑 𝑔 𝑚 𝑜 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 fldext2chn.3 . . 3 (𝜑 → 0 < (♯‘𝑇))
2 fveq2 6881 . . . . . 6 (𝑑 = ∅ → (♯‘𝑑) = (♯‘∅))
32breq2d 5120 . . . . 5 (𝑑 = ∅ → (0 < (♯‘𝑑) ↔ 0 < (♯‘∅)))
4 fveq2 6881 . . . . . . . 8 (𝑑 = ∅ → (lastS‘𝑑) = (lastS‘∅))
54oveq2d 7428 . . . . . . 7 (𝑑 = ∅ → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘∅)))
6 fveq1 6880 . . . . . . . 8 (𝑑 = ∅ → (𝑑‘0) = (∅‘0))
76oveq2d 7428 . . . . . . 7 (𝑑 = ∅ → (𝑊s (𝑑‘0)) = (𝑊s (∅‘0)))
85, 7breq12d 5121 . . . . . 6 (𝑑 = ∅ → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘∅))/FldExt(𝑊s (∅‘0))))
95, 7oveq12d 7430 . . . . . . . 8 (𝑑 = ∅ → ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = ((𝑊s (lastS‘∅))[:](𝑊s (∅‘0))))
109eqeq1d 2764 . . . . . . 7 (𝑑 = ∅ → (((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊s (lastS‘∅))[:](𝑊s (∅‘0))) = (2↑𝑛)))
1110rexbidv 3188 . . . . . 6 (𝑑 = ∅ → (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘∅))[:](𝑊s (∅‘0))) = (2↑𝑛)))
128, 11anbi12d 643 . . . . 5 (𝑑 = ∅ → (((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊s (lastS‘∅))/FldExt(𝑊s (∅‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘∅))[:](𝑊s (∅‘0))) = (2↑𝑛))))
133, 12imbi12d 347 . . . 4 (𝑑 = ∅ → ((0 < (♯‘𝑑) → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘∅) → ((𝑊s (lastS‘∅))/FldExt(𝑊s (∅‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘∅))[:](𝑊s (∅‘0))) = (2↑𝑛)))))
14 fveq2 6881 . . . . . 6 (𝑑 = 𝑐 → (♯‘𝑑) = (♯‘𝑐))
1514breq2d 5120 . . . . 5 (𝑑 = 𝑐 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑐)))
16 fveq2 6881 . . . . . . . 8 (𝑑 = 𝑐 → (lastS‘𝑑) = (lastS‘𝑐))
1716oveq2d 7428 . . . . . . 7 (𝑑 = 𝑐 → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘𝑐)))
18 fveq1 6880 . . . . . . . 8 (𝑑 = 𝑐 → (𝑑‘0) = (𝑐‘0))
1918oveq2d 7428 . . . . . . 7 (𝑑 = 𝑐 → (𝑊s (𝑑‘0)) = (𝑊s (𝑐‘0)))
2017, 19breq12d 5121 . . . . . 6 (𝑑 = 𝑐 → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0))))
2117, 19oveq12d 7430 . . . . . . . 8 (𝑑 = 𝑐 → ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))))
2221eqeq1d 2764 . . . . . . 7 (𝑑 = 𝑐 → (((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))
2322rexbidv 3188 . . . . . 6 (𝑑 = 𝑐 → (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))
2420, 23anbi12d 643 . . . . 5 (𝑑 = 𝑐 → (((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛))))
2515, 24imbi12d 347 . . . 4 (𝑑 = 𝑐 → ((0 < (♯‘𝑑) → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))))
26 fveq2 6881 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (♯‘𝑑) = (♯‘(𝑐 ++ ⟨“𝑔”⟩)))
2726breq2d 5120 . . . . 5 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (0 < (♯‘𝑑) ↔ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))))
28 fveq2 6881 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (lastS‘𝑑) = (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))
2928oveq2d 7428 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))))
30 fveq1 6880 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑑‘0) = ((𝑐 ++ ⟨“𝑔”⟩)‘0))
3130oveq2d 7428 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊s (𝑑‘0)) = (𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
3229, 31breq12d 5121 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))))
3329, 31oveq12d 7430 . . . . . . . . 9 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))))
3433eqeq1d 2764 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛)))
3534rexbidv 3188 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛)))
36 oveq2 7420 . . . . . . . . 9 (𝑛 = 𝑚 → (2↑𝑛) = (2↑𝑚))
3736eqeq2d 2773 . . . . . . . 8 (𝑛 = 𝑚 → (((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛) ↔ ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
3837cbvrexvw 3243 . . . . . . 7 (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛) ↔ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
3935, 38bitrdi 290 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
4032, 39anbi12d 643 . . . . 5 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))))
4127, 40imbi12d 347 . . . 4 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((0 < (♯‘𝑑) → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩)) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))))
42 fveq2 6881 . . . . . 6 (𝑑 = 𝑇 → (♯‘𝑑) = (♯‘𝑇))
4342breq2d 5120 . . . . 5 (𝑑 = 𝑇 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑇)))
44 fveq2 6881 . . . . . . . 8 (𝑑 = 𝑇 → (lastS‘𝑑) = (lastS‘𝑇))
4544oveq2d 7428 . . . . . . 7 (𝑑 = 𝑇 → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘𝑇)))
46 fveq1 6880 . . . . . . . 8 (𝑑 = 𝑇 → (𝑑‘0) = (𝑇‘0))
4746oveq2d 7428 . . . . . . 7 (𝑑 = 𝑇 → (𝑊s (𝑑‘0)) = (𝑊s (𝑇‘0)))
4845, 47breq12d 5121 . . . . . 6 (𝑑 = 𝑇 → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0))))
4945, 47oveq12d 7430 . . . . . . . 8 (𝑑 = 𝑇 → ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))))
5049eqeq1d 2764 . . . . . . 7 (𝑑 = 𝑇 → (((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛)))
5150rexbidv 3188 . . . . . 6 (𝑑 = 𝑇 → (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛)))
5248, 51anbi12d 643 . . . . 5 (𝑑 = 𝑇 → (((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛))))
5343, 52imbi12d 347 . . . 4 (𝑑 = 𝑇 → ((0 < (♯‘𝑑) → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑑))[:](𝑊s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘𝑇) → ((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛)))))
54 fldext2chn.t . . . 4 (𝜑𝑇 ∈ ( < Chain (SubDRing‘𝑊)))
55 0re 11216 . . . . . . . 8 0 ∈ ℝ
5655ltnri 11325 . . . . . . 7 ¬ 0 < 0
5756a1i 11 . . . . . 6 (𝜑 → ¬ 0 < 0)
58 hash0 14410 . . . . . . 7 (♯‘∅) = 0
5958breq2i 5116 . . . . . 6 (0 < (♯‘∅) ↔ 0 < 0)
6057, 59sylnibr 332 . . . . 5 (𝜑 → ¬ 0 < (♯‘∅))
6160pm2.21d 122 . . . 4 (𝜑 → (0 < (♯‘∅) → ((𝑊s (lastS‘∅))/FldExt(𝑊s (∅‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘∅))[:](𝑊s (∅‘0))) = (2↑𝑛))))
62 fldext2chn.w . . . . . . . . . . 11 (𝜑𝑊 ∈ Field)
6362ad6antr 748 . . . . . . . . . 10 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑊 ∈ Field)
64 simp-5r 797 . . . . . . . . . 10 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑔 ∈ (SubDRing‘𝑊))
65 fldsdrgfld 20912 . . . . . . . . . 10 ((𝑊 ∈ Field ∧ 𝑔 ∈ (SubDRing‘𝑊)) → (𝑊s 𝑔) ∈ Field)
6663, 64, 65syl2anc 595 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊s 𝑔) ∈ Field)
67 fldextid 34058 . . . . . . . . 9 ((𝑊s 𝑔) ∈ Field → (𝑊s 𝑔)/FldExt(𝑊s 𝑔))
6866, 67syl 18 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊s 𝑔)/FldExt(𝑊s 𝑔))
69 simp-5r 797 . . . . . . . . . . . 12 ((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) → 𝑐 ∈ ( < Chain (SubDRing‘𝑊)))
7069chnwrd 18670 . . . . . . . . . . 11 ((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) → 𝑐 ∈ Word (SubDRing‘𝑊))
7170adantr 485 . . . . . . . . . 10 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑐 ∈ Word (SubDRing‘𝑊))
72 lswccats1 14679 . . . . . . . . . 10 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ 𝑔 ∈ (SubDRing‘𝑊)) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
7371, 64, 72syl2anc 595 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
7473oveq2d 7428 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))) = (𝑊s 𝑔))
75 simpr 489 . . . . . . . . . . . . 13 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑐 = ∅)
7675oveq1d 7427 . . . . . . . . . . . 12 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑐 ++ ⟨“𝑔”⟩) = (∅ ++ ⟨“𝑔”⟩))
77 s0s1 14966 . . . . . . . . . . . 12 ⟨“𝑔”⟩ = (∅ ++ ⟨“𝑔”⟩)
7876, 77eqtr4di 2815 . . . . . . . . . . 11 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑐 ++ ⟨“𝑔”⟩) = ⟨“𝑔”⟩)
7978fveq1d 6883 . . . . . . . . . 10 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (⟨“𝑔”⟩‘0))
80 s1fv 14655 . . . . . . . . . . 11 (𝑔 ∈ (SubDRing‘𝑊) → (⟨“𝑔”⟩‘0) = 𝑔)
8164, 80syl 18 . . . . . . . . . 10 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (⟨“𝑔”⟩‘0) = 𝑔)
8279, 81eqtrd 2797 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = 𝑔)
8382oveq2d 7428 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) = (𝑊s 𝑔))
8468, 74, 833brtr4d 5142 . . . . . . 7 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
85 oveq2 7420 . . . . . . . . . 10 (𝑚 = 0 → (2↑𝑚) = (2↑0))
86 2cn 12322 . . . . . . . . . . 11 2 ∈ ℂ
87 exp0 14108 . . . . . . . . . . 11 (2 ∈ ℂ → (2↑0) = 1)
8886, 87ax-mp 5 . . . . . . . . . 10 (2↑0) = 1
8985, 88eqtrdi 2813 . . . . . . . . 9 (𝑚 = 0 → (2↑𝑚) = 1)
9089eqeq2d 2773 . . . . . . . 8 (𝑚 = 0 → (((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚) ↔ ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = 1))
91 0nn0 12525 . . . . . . . . 9 0 ∈ ℕ0
9291a1i 11 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 0 ∈ ℕ0)
9374, 83oveq12d 7430 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = ((𝑊s 𝑔)[:](𝑊s 𝑔)))
94 extdgid 34059 . . . . . . . . . 10 ((𝑊s 𝑔) ∈ Field → ((𝑊s 𝑔)[:](𝑊s 𝑔)) = 1)
9566, 94syl 18 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊s 𝑔)[:](𝑊s 𝑔)) = 1)
9693, 95eqtrd 2797 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = 1)
9790, 92, 96rspcedvdw 3583 . . . . . . 7 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
9884, 97jca 520 . . . . . 6 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
99 simp-6r 799 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔))
100 simpllr 787 . . . . . . . . . . . . . 14 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 𝑐 ≠ ∅)
101100neneqd 2962 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ¬ 𝑐 = ∅)
10299, 101orcnd 891 . . . . . . . . . . . 12 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (lastS‘𝑐) < 𝑔)
10370ad3antrrr 742 . . . . . . . . . . . . . 14 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 𝑐 ∈ Word (SubDRing‘𝑊))
104 lswcl 14612 . . . . . . . . . . . . . 14 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ 𝑐 ≠ ∅) → (lastS‘𝑐) ∈ (SubDRing‘𝑊))
105103, 100, 104syl2anc 595 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (lastS‘𝑐) ∈ (SubDRing‘𝑊))
106 simp-7r 801 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 𝑔 ∈ (SubDRing‘𝑊))
107 fldext2chn.e . . . . . . . . . . . . . . . . . 18 𝐸 = (𝑊s 𝑒)
108 fldext2chn.f . . . . . . . . . . . . . . . . . 18 𝐹 = (𝑊s 𝑓)
109107, 108breq12i 5117 . . . . . . . . . . . . . . . . 17 (𝐸/FldExt𝐹 ↔ (𝑊s 𝑒)/FldExt(𝑊s 𝑓))
110107, 108oveq12i 7424 . . . . . . . . . . . . . . . . . 18 (𝐸[:]𝐹) = ((𝑊s 𝑒)[:](𝑊s 𝑓))
111110eqeq1i 2767 . . . . . . . . . . . . . . . . 17 ((𝐸[:]𝐹) = 2 ↔ ((𝑊s 𝑒)[:](𝑊s 𝑓)) = 2)
112109, 111anbi12i 639 . . . . . . . . . . . . . . . 16 ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊s 𝑒)/FldExt(𝑊s 𝑓) ∧ ((𝑊s 𝑒)[:](𝑊s 𝑓)) = 2))
113 oveq2 7420 . . . . . . . . . . . . . . . . . . 19 (𝑒 = 𝑔 → (𝑊s 𝑒) = (𝑊s 𝑔))
114113adantr 485 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → (𝑊s 𝑒) = (𝑊s 𝑔))
115 oveq2 7420 . . . . . . . . . . . . . . . . . . 19 (𝑓 = (lastS‘𝑐) → (𝑊s 𝑓) = (𝑊s (lastS‘𝑐)))
116115adantl 486 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → (𝑊s 𝑓) = (𝑊s (lastS‘𝑐)))
117114, 116breq12d 5121 . . . . . . . . . . . . . . . . 17 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → ((𝑊s 𝑒)/FldExt(𝑊s 𝑓) ↔ (𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐))))
118114, 116oveq12d 7430 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → ((𝑊s 𝑒)[:](𝑊s 𝑓)) = ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))))
119118eqeq1d 2764 . . . . . . . . . . . . . . . . 17 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → (((𝑊s 𝑒)[:](𝑊s 𝑓)) = 2 ↔ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2))
120117, 119anbi12d 643 . . . . . . . . . . . . . . . 16 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → (((𝑊s 𝑒)/FldExt(𝑊s 𝑓) ∧ ((𝑊s 𝑒)[:](𝑊s 𝑓)) = 2) ↔ ((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2)))
121112, 120bitrid 286 . . . . . . . . . . . . . . 15 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2)))
122121ancoms 463 . . . . . . . . . . . . . 14 ((𝑓 = (lastS‘𝑐) ∧ 𝑒 = 𝑔) → ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2)))
123 fldext2chn.l . . . . . . . . . . . . . 14 < = {⟨𝑓, 𝑒⟩ ∣ (𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2)}
124122, 123brabga 5517 . . . . . . . . . . . . 13 (((lastS‘𝑐) ∈ (SubDRing‘𝑊) ∧ 𝑔 ∈ (SubDRing‘𝑊)) → ((lastS‘𝑐) < 𝑔 ↔ ((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2)))
125105, 106, 124syl2anc 595 . . . . . . . . . . . 12 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((lastS‘𝑐) < 𝑔 ↔ ((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2)))
126102, 125mpbid 235 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2))
127126simpld 499 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)))
128 hashgt0 14431 . . . . . . . . . . . . . 14 ((𝑐 ∈ ( < Chain (SubDRing‘𝑊)) ∧ 𝑐 ≠ ∅) → 0 < (♯‘𝑐))
12969, 128sylan 591 . . . . . . . . . . . . 13 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → 0 < (♯‘𝑐))
130 simpllr 787 . . . . . . . . . . . . 13 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛))))
131129, 130mpd 16 . . . . . . . . . . . 12 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))
132131simprd 500 . . . . . . . . . . 11 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛))
133 oveq2 7420 . . . . . . . . . . . . 13 (𝑛 = 𝑜 → (2↑𝑛) = (2↑𝑜))
134133eqeq2d 2773 . . . . . . . . . . . 12 (𝑛 = 𝑜 → (((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛) ↔ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)))
135134cbvrexvw 3243 . . . . . . . . . . 11 (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛) ↔ ∃𝑜 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜))
136132, 135sylib 221 . . . . . . . . . 10 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ∃𝑜 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜))
137127, 136r19.29a 3172 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)))
138131simpld 499 . . . . . . . . 9 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)))
139 fldexttr 34057 . . . . . . . . 9 (((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0))) → (𝑊s 𝑔)/FldExt(𝑊s (𝑐‘0)))
140137, 138, 139syl2anc 595 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊s 𝑔)/FldExt(𝑊s (𝑐‘0)))
141103, 106, 72syl2anc 595 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
142141oveq2d 7428 . . . . . . . . 9 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))) = (𝑊s 𝑔))
143142, 136r19.29a 3172 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))) = (𝑊s 𝑔))
144106s1cld 14648 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ⟨“𝑔”⟩ ∈ Word (SubDRing‘𝑊))
145129ad2antrr 738 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 0 < (♯‘𝑐))
146 ccatfv0 14628 . . . . . . . . . . 11 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ ⟨“𝑔”⟩ ∈ Word (SubDRing‘𝑊) ∧ 0 < (♯‘𝑐)) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (𝑐‘0))
147103, 144, 145, 146syl3anc 1397 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (𝑐‘0))
148147oveq2d 7428 . . . . . . . . 9 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) = (𝑊s (𝑐‘0)))
149148, 136r19.29a 3172 . . . . . . . 8 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) = (𝑊s (𝑐‘0)))
150140, 143, 1493brtr4d 5142 . . . . . . 7 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
151 oveq2 7420 . . . . . . . . . 10 (𝑚 = (𝑜 + 1) → (2↑𝑚) = (2↑(𝑜 + 1)))
152151eqeq2d 2773 . . . . . . . . 9 (𝑚 = (𝑜 + 1) → (((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚) ↔ ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑(𝑜 + 1))))
153 simplr 780 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 𝑜 ∈ ℕ0)
154 1nn0 12526 . . . . . . . . . . 11 1 ∈ ℕ0
155154a1i 11 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 1 ∈ ℕ0)
156153, 155nn0addcld 12575 . . . . . . . . 9 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (𝑜 + 1) ∈ ℕ0)
157142, 148oveq12d 7430 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = ((𝑊s 𝑔)[:](𝑊s (𝑐‘0))))
158138ad2antrr 738 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)))
159 extdgmul 34062 . . . . . . . . . . 11 (((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0))) → ((𝑊s 𝑔)[:](𝑊s (𝑐‘0))) = (((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) ·e ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0)))))
160127, 158, 159syl2anc 595 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑊s 𝑔)[:](𝑊s (𝑐‘0))) = (((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) ·e ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0)))))
16186a1i 11 . . . . . . . . . . . 12 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 2 ∈ ℂ)
162161, 153expcld 14189 . . . . . . . . . . . 12 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (2↑𝑜) ∈ ℂ)
163161, 162mulcomd 11236 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (2 · (2↑𝑜)) = ((2↑𝑜) · 2))
164126simprd 500 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) = 2)
165 simpr 489 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜))
166164, 165oveq12d 7430 . . . . . . . . . . . 12 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) ·e ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0)))) = (2 ·e (2↑𝑜)))
167 2re 12321 . . . . . . . . . . . . . 14 2 ∈ ℝ
168167a1i 11 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → 2 ∈ ℝ)
169168, 153reexpcld 14206 . . . . . . . . . . . . 13 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (2↑𝑜) ∈ ℝ)
170 rexmul 13303 . . . . . . . . . . . . 13 ((2 ∈ ℝ ∧ (2↑𝑜) ∈ ℝ) → (2 ·e (2↑𝑜)) = (2 · (2↑𝑜)))
171168, 169, 170syl2anc 595 . . . . . . . . . . . 12 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (2 ·e (2↑𝑜)) = (2 · (2↑𝑜)))
172166, 171eqtrd 2797 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) ·e ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0)))) = (2 · (2↑𝑜)))
173161, 153expp1d 14190 . . . . . . . . . . 11 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (2↑(𝑜 + 1)) = ((2↑𝑜) · 2))
174163, 172, 1733eqtr4d 2807 . . . . . . . . . 10 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → (((𝑊s 𝑔)[:](𝑊s (lastS‘𝑐))) ·e ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0)))) = (2↑(𝑜 + 1)))
175157, 160, 1743eqtrd 2801 . . . . . . . . 9 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑(𝑜 + 1)))
176152, 156, 175rspcedvdw 3583 . . . . . . . 8 (((((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑜)) → ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
177176, 136r19.29a 3172 . . . . . . 7 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
178150, 177jca 520 . . . . . 6 (((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
17998, 178pm2.61dane 3044 . . . . 5 ((((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
180179ex 417 . . . 4 (((((𝜑𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑐))[:](𝑊s (𝑐‘0))) = (2↑𝑛)))) → (0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩)) → ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))))
18113, 25, 41, 53, 54, 61, 180chnind 18683 . . 3 (𝜑 → (0 < (♯‘𝑇) → ((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛))))
1821, 181mpd 16 . 2 (𝜑 → ((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛)))
183 fldext2chn.2 . . . 4 (𝜑 → (𝑊s (lastS‘𝑇)) = 𝐿)
184 fldext2chn.1 . . . 4 (𝜑 → (𝑊s (𝑇‘0)) = 𝑄)
185183, 184breq12d 5121 . . 3 (𝜑 → ((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ↔ 𝐿/FldExt𝑄))
186183, 184oveq12d 7430 . . . . 5 (𝜑 → ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (𝐿[:]𝑄))
187186eqeq1d 2764 . . . 4 (𝜑 → (((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛) ↔ (𝐿[:]𝑄) = (2↑𝑛)))
188187rexbidv 3188 . . 3 (𝜑 → (∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 (𝐿[:]𝑄) = (2↑𝑛)))
189185, 188anbi12d 643 . 2 (𝜑 → (((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊s (lastS‘𝑇))[:](𝑊s (𝑇‘0))) = (2↑𝑛)) ↔ (𝐿/FldExt𝑄 ∧ ∃𝑛 ∈ ℕ0 (𝐿[:]𝑄) = (2↑𝑛))))
190182, 189mpbid 235 1 (𝜑 → (𝐿/FldExt𝑄 ∧ ∃𝑛 ∈ ℕ0 (𝐿[:]𝑄) = (2↑𝑛)))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ¬ wn 3  wi 4  wb 209  wa 400  wo 860   = wceq 1569  wcel 2142  wne 2957  wrex 3088  c0 4285   class class class wbr 5108  {copab 5172  cfv 6536  (class class class)co 7412  cc 11104  cr 11105  0cc0 11106  1c1 11107   + caddc 11109   · cmul 11111   < clt 11249  2c2 12301  0cn0 12510   ·e cxmu 13142  cexp 14104  chash 14373  Word cword 14557  lastSclsw 14606   ++ cconcat 14614  ⟨“cs1 14640  s cress 17296   Chain cchn 18667  Fieldcfield 20839  SubDRingcsdrg 20900  /FldExtcfldext 34037  [:]cextdg 34039
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-8 2144  ax-9 2152  ax-10 2175  ax-11 2191  ax-12 2212  ax-ext 2734  ax-rep 5237  ax-sep 5256  ax-nul 5268  ax-pow 5335  ax-pr 5403  ax-un 7734  ax-reg 9552  ax-inf2 9608  ax-ac2 10453  ax-cnex 11162  ax-resscn 11163  ax-1cn 11164  ax-icn 11165  ax-addcl 11166  ax-addrcl 11167  ax-mulcl 11168  ax-mulrcl 11169  ax-mulcom 11170  ax-addass 11171  ax-mulass 11172  ax-distr 11173  ax-i2m1 11174  ax-1ne0 11175  ax-1rid 11176  ax-rnegex 11177  ax-rrecex 11178  ax-cnre 11179  ax-pre-lttri 11180  ax-pre-lttrn 11181  ax-pre-ltadd 11182  ax-pre-mulgt0 11183
This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3or 1103  df-3an 1104  df-tru 1572  df-fal 1582  df-ex 1809  df-nf 1813  df-sb 2096  df-mo 2566  df-eu 2596  df-clab 2741  df-cleq 2754  df-clel 2837  df-nfc 2911  df-ne 2958  df-nel 3064  df-ral 3079  df-rex 3089  df-rmo 3368  df-reu 3369  df-rab 3416  df-v 3456  df-sbc 3744  df-csb 3853  df-dif 3907  df-un 3909  df-in 3911  df-ss 3921  df-pss 3924  df-nul 4286  df-if 4487  df-pw 4563  df-sn 4589  df-pr 4591  df-tp 4593  df-op 4595  df-uni 4872  df-int 4912  df-iun 4957  df-iin 4958  df-br 5109  df-opab 5173  df-mpt 5192  df-tr 5218  df-id 5555  df-eprel 5560  df-po 5568  df-so 5569  df-fr 5613  df-se 5614  df-we 5615  df-xp 5666  df-rel 5667  df-cnv 5668  df-co 5669  df-dm 5670  df-rn 5671  df-res 5672  df-ima 5673  df-pred 6302  df-ord 6363  df-on 6364  df-lim 6365  df-suc 6366  df-iota 6492  df-fun 6538  df-fn 6539  df-f 6540  df-f1 6541  df-fo 6542  df-f1o 6543  df-fv 6544  df-isom 6545  df-riota 7369  df-ov 7415  df-oprab 7416  df-mpo 7417  df-of 7676  df-rpss 7722  df-om 7861  df-1st 7984  df-2nd 7985  df-supp 8155  df-tpos 8220  df-frecs 8276  df-wrecs 8307  df-recs 8356  df-rdg 8395  df-1o 8451  df-2o 8452  df-oadd 8455  df-er 8692  df-map 8824  df-ixp 8894  df-en 8942  df-dom 8943  df-sdom 8944  df-fin 8945  df-fsupp 9320  df-sup 9400  df-oi 9470  df-r1 9734  df-rank 9735  df-scott 9856  df-dju 9894  df-card 9932  df-acn 9935  df-ac 10107  df-pnf 11251  df-mnf 11252  df-xr 11253  df-ltxr 11254  df-le 11255  df-sub 11449  df-neg 11450  df-nn 12240  df-2 12309  df-3 12310  df-4 12311  df-5 12312  df-6 12313  df-7 12314  df-8 12315  df-9 12316  df-n0 12511  df-xnn0 12584  df-z 12598  df-dec 12718  df-uz 12869  df-rp 13023  df-xmul 13145  df-fz 13542  df-fzo 13690  df-seq 14045  df-exp 14105  df-hash 14374  df-word 14558  df-lsw 14607  df-concat 14615  df-s1 14641  df-substr 14686  df-pfx 14716  df-struct 17213  df-sets 17230  df-slot 17248  df-ndx 17260  df-base 17276  df-ress 17297  df-plusg 17329  df-mulr 17330  df-sca 17332  df-vsca 17333  df-ip 17334  df-tset 17335  df-ple 17336  df-ocomp 17337  df-ds 17338  df-hom 17340  df-cco 17341  df-0g 17500  df-gsum 17501  df-prds 17506  df-pws 17508  df-mre 17644  df-mrc 17645  df-mri 17646  df-acs 17647  df-proset 18356  df-drs 18357  df-poset 18375  df-ipo 18590  df-chn 18668  df-mgm 18704  df-sgrp 18783  df-mnd 18799  df-mhm 18847  df-submnd 18848  df-grp 19009  df-minusg 19010  df-sbg 19011  df-mulg 19140  df-subg 19195  df-ghm 19290  df-cntz 19393  df-cmn 19858  df-abl 19859  df-mgp 20223  df-rng 20237  df-ur 20270  df-ring 20323  df-cring 20324  df-oppr 20426  df-dvdsr 20446  df-unit 20447  df-invr 20477  df-nzr 20621  df-subrng 20656  df-subrg 20680  df-drng 20840  df-field 20841  df-sdrg 20901  df-lmod 20994  df-lss 21064  df-lsp 21104  df-lmhm 21154  df-lbs 21207  df-lvec 21235  df-sra 21305  df-rgmod 21306  df-lidl 21343  df-rsp 21344  df-dsmm 21893  df-frlm 21908  df-uvc 21944  df-lindf 21967  df-linds 21968  df-dim 33999  df-fldext 34040  df-extdg 34041
This theorem is used by:  constrext2chnlem  34149
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