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Theorem fldext2chn 34240
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 6882 . . . . . 6 (𝑑 = ∅ → (♯‘𝑑) = (♯‘∅))
32breq2d 5119 . . . . 5 (𝑑 = ∅ → (0 < (♯‘𝑑) ↔ 0 < (♯‘∅)))
4 fveq2 6882 . . . . . . . 8 (𝑑 = ∅ → (lastS‘𝑑) = (lastS‘∅))
54oveq2d 7432 . . . . . . 7 (𝑑 = ∅ → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘∅)))
6 fveq1 6881 . . . . . . . 8 (𝑑 = ∅ → (𝑑‘0) = (∅‘0))
76oveq2d 7432 . . . . . . 7 (𝑑 = ∅ → (𝑊s (𝑑‘0)) = (𝑊s (∅‘0)))
85, 7breq12d 5120 . . . . . 6 (𝑑 = ∅ → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘∅))/FldExt(𝑊s (∅‘0))))
95, 7oveq12d 7434 . . . . . . . 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 644 . . . . 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 6882 . . . . . 6 (𝑑 = 𝑐 → (♯‘𝑑) = (♯‘𝑐))
1514breq2d 5119 . . . . 5 (𝑑 = 𝑐 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑐)))
16 fveq2 6882 . . . . . . . 8 (𝑑 = 𝑐 → (lastS‘𝑑) = (lastS‘𝑐))
1716oveq2d 7432 . . . . . . 7 (𝑑 = 𝑐 → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘𝑐)))
18 fveq1 6881 . . . . . . . 8 (𝑑 = 𝑐 → (𝑑‘0) = (𝑐‘0))
1918oveq2d 7432 . . . . . . 7 (𝑑 = 𝑐 → (𝑊s (𝑑‘0)) = (𝑊s (𝑐‘0)))
2017, 19breq12d 5120 . . . . . 6 (𝑑 = 𝑐 → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0))))
2117, 19oveq12d 7434 . . . . . . . 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 644 . . . . 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 6882 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (♯‘𝑑) = (♯‘(𝑐 ++ ⟨“𝑔”⟩)))
2726breq2d 5119 . . . . 5 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (0 < (♯‘𝑑) ↔ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))))
28 fveq2 6882 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (lastS‘𝑑) = (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))
2928oveq2d 7432 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))))
30 fveq1 6881 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑑‘0) = ((𝑐 ++ ⟨“𝑔”⟩)‘0))
3130oveq2d 7432 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊s (𝑑‘0)) = (𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
3229, 31breq12d 5120 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊s ((𝑐 ++ ⟨“𝑔”⟩)‘0))))
3329, 31oveq12d 7434 . . . . . . . . 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 7424 . . . . . . . . 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 644 . . . . 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 6882 . . . . . 6 (𝑑 = 𝑇 → (♯‘𝑑) = (♯‘𝑇))
4342breq2d 5119 . . . . 5 (𝑑 = 𝑇 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑇)))
44 fveq2 6882 . . . . . . . 8 (𝑑 = 𝑇 → (lastS‘𝑑) = (lastS‘𝑇))
4544oveq2d 7432 . . . . . . 7 (𝑑 = 𝑇 → (𝑊s (lastS‘𝑑)) = (𝑊s (lastS‘𝑇)))
46 fveq1 6881 . . . . . . . 8 (𝑑 = 𝑇 → (𝑑‘0) = (𝑇‘0))
4746oveq2d 7432 . . . . . . 7 (𝑑 = 𝑇 → (𝑊s (𝑑‘0)) = (𝑊s (𝑇‘0)))
4845, 47breq12d 5120 . . . . . 6 (𝑑 = 𝑇 → ((𝑊s (lastS‘𝑑))/FldExt(𝑊s (𝑑‘0)) ↔ (𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0))))
4945, 47oveq12d 7434 . . . . . . . 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 644 . . . . 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 11237 . . . . . . . 8 0 ∈ ℝ
5655ltnri 11346 . . . . . . 7 ¬ 0 < 0
5756a1i 11 . . . . . 6 (𝜑 → ¬ 0 < 0)
58 hash0 14433 . . . . . . 7 (♯‘∅) = 0
5958breq2i 5115 . . . . . 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 749 . . . . . . . . . 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 798 . . . . . . . . . 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 20968 . . . . . . . . . 10 ((𝑊 ∈ Field ∧ 𝑔 ∈ (SubDRing‘𝑊)) → (𝑊s 𝑔) ∈ Field)
6663, 64, 65syl2anc 596 . . . . . . . . 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 34171 . . . . . . . . 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 798 . . . . . . . . . . . 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 18700 . . . . . . . . . . 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 486 . . . . . . . . . 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 14704 . . . . . . . . . 10 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ 𝑔 ∈ (SubDRing‘𝑊)) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
7371, 64, 72syl2anc 596 . . . . . . . . 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 7432 . . . . . . . 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 490 . . . . . . . . . . . . 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 7431 . . . . . . . . . . . 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 14995 . . . . . . . . . . . 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 6884 . . . . . . . . . 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 14680 . . . . . . . . . . 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 7432 . . . . . . . 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 5141 . . . . . . 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 7424 . . . . . . . . . 10 (𝑚 = 0 → (2↑𝑚) = (2↑0))
86 2cn 12343 . . . . . . . . . . 11 2 ∈ ℂ
87 exp0 14131 . . . . . . . . . . 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 12546 . . . . . . . . 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 7434 . . . . . . . . 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 34172 . . . . . . . . . 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 3582 . . . . . . 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 521 . . . . . 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 800 . . . . . . . . . . . . 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 788 . . . . . . . . . . . . . 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 892 . . . . . . . . . . . 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 743 . . . . . . . . . . . . . 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 14635 . . . . . . . . . . . . . 14 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ 𝑐 ≠ ∅) → (lastS‘𝑐) ∈ (SubDRing‘𝑊))
105103, 100, 104syl2anc 596 . . . . . . . . . . . . 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 802 . . . . . . . . . . . . 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 5116 . . . . . . . . . . . . . . . . 17 (𝐸/FldExt𝐹 ↔ (𝑊s 𝑒)/FldExt(𝑊s 𝑓))
110107, 108oveq12i 7428 . . . . . . . . . . . . . . . . . 18 (𝐸[:]𝐹) = ((𝑊s 𝑒)[:](𝑊s 𝑓))
111110eqeq1i 2767 . . . . . . . . . . . . . . . . 17 ((𝐸[:]𝐹) = 2 ↔ ((𝑊s 𝑒)[:](𝑊s 𝑓)) = 2)
112109, 111anbi12i 640 . . . . . . . . . . . . . . . 16 ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊s 𝑒)/FldExt(𝑊s 𝑓) ∧ ((𝑊s 𝑒)[:](𝑊s 𝑓)) = 2))
113 oveq2 7424 . . . . . . . . . . . . . . . . . . 19 (𝑒 = 𝑔 → (𝑊s 𝑒) = (𝑊s 𝑔))
114113adantr 486 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → (𝑊s 𝑒) = (𝑊s 𝑔))
115 oveq2 7424 . . . . . . . . . . . . . . . . . . 19 (𝑓 = (lastS‘𝑐) → (𝑊s 𝑓) = (𝑊s (lastS‘𝑐)))
116115adantl 487 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → (𝑊s 𝑓) = (𝑊s (lastS‘𝑐)))
117114, 116breq12d 5120 . . . . . . . . . . . . . . . . 17 ((𝑒 = 𝑔𝑓 = (lastS‘𝑐)) → ((𝑊s 𝑒)/FldExt(𝑊s 𝑓) ↔ (𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐))))
118114, 116oveq12d 7434 . . . . . . . . . . . . . . . . . 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 644 . . . . . . . . . . . . . . . 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 464 . . . . . . . . . . . . . 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 5516 . . . . . . . . . . . . 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 596 . . . . . . . . . . . 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 500 . . . . . . . . . 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 14454 . . . . . . . . . . . . . 14 ((𝑐 ∈ ( < Chain (SubDRing‘𝑊)) ∧ 𝑐 ≠ ∅) → 0 < (♯‘𝑐))
12969, 128sylan 592 . . . . . . . . . . . . 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 788 . . . . . . . . . . . . 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 501 . . . . . . . . . . 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 7424 . . . . . . . . . . . . 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 500 . . . . . . . . 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 34170 . . . . . . . . 9 (((𝑊s 𝑔)/FldExt(𝑊s (lastS‘𝑐)) ∧ (𝑊s (lastS‘𝑐))/FldExt(𝑊s (𝑐‘0))) → (𝑊s 𝑔)/FldExt(𝑊s (𝑐‘0)))
140137, 138, 139syl2anc 596 . . . . . . . 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 596 . . . . . . . . . 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 7432 . . . . . . . . 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 14672 . . . . . . . . . . 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 739 . . . . . . . . . . 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 14651 . . . . . . . . . . 11 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ ⟨“𝑔”⟩ ∈ Word (SubDRing‘𝑊) ∧ 0 < (♯‘𝑐)) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (𝑐‘0))
147103, 144, 145, 146syl3anc 1398 . . . . . . . . . 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 7432 . . . . . . . . 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 5141 . . . . . . 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 7424 . . . . . . . . . 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 781 . . . . . . . . . 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 12547 . . . . . . . . . . 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 12596 . . . . . . . . 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 7434 . . . . . . . . . 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 739 . . . . . . . . . . 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 34175 . . . . . . . . . . 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 596 . . . . . . . . . 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 14212 . . . . . . . . . . . 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 11257 . . . . . . . . . . 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 501 . . . . . . . . . . . . 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 490 . . . . . . . . . . . . 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 7434 . . . . . . . . . . . 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 12342 . . . . . . . . . . . . . 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 14229 . . . . . . . . . . . . 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 13325 . . . . . . . . . . . . 13 ((2 ∈ ℝ ∧ (2↑𝑜) ∈ ℝ) → (2 ·e (2↑𝑜)) = (2 · (2↑𝑜)))
171168, 169, 170syl2anc 596 . . . . . . . . . . . 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 14213 . . . . . . . . . . 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 3582 . . . . . . . 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 521 . . . . . 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 418 . . . 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 18713 . . 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 5120 . . 3 (𝜑 → ((𝑊s (lastS‘𝑇))/FldExt(𝑊s (𝑇‘0)) ↔ 𝐿/FldExt𝑄))
186183, 184oveq12d 7434 . . . . 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 644 . 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 401  wo 861   = wceq 1570  wcel 2145  wne 2957  wrex 3088  c0 4282   class class class wbr 5107  {copab 5171  cfv 6537  (class class class)co 7416  cc 11125  cr 11126  0cc0 11127  1c1 11128   + caddc 11130   · cmul 11132   < clt 11270  2c2 12322  0cn0 12531   ·e cxmu 13164  cexp 14127  chash 14396  Word cword 14580  lastSclsw 14629   ++ cconcat 14637  ⟨“cs1 14664  s cress 17326   Chain cchn 18697  Fieldcfield 20895  SubDRingcsdrg 20956  /FldExtcfldext 34150  [:]cextdg 34152
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2215  ax-ext 2734  ax-rep 5236  ax-sep 5255  ax-nul 5267  ax-pow 5334  ax-pr 5402  ax-un 7739  ax-reg 9567  ax-inf2 9623  ax-ac2 10468  ax-cnex 11183  ax-resscn 11184  ax-1cn 11185  ax-icn 11186  ax-addcl 11187  ax-addrcl 11188  ax-mulcl 11189  ax-mulrcl 11190  ax-mulcom 11191  ax-addass 11192  ax-mulass 11193  ax-distr 11194  ax-i2m1 11195  ax-1ne0 11196  ax-1rid 11197  ax-rnegex 11198  ax-rrecex 11199  ax-cnre 11200  ax-pre-lttri 11201  ax-pre-lttrn 11202  ax-pre-ltadd 11203  ax-pre-mulgt0 11204
This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3or 1104  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  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 3367  df-reu 3368  df-rab 3415  df-v 3455  df-sbc 3743  df-csb 3851  df-dif 3905  df-un 3907  df-in 3909  df-ss 3919  df-pss 3922  df-nul 4283  df-if 4486  df-pw 4562  df-sn 4588  df-pr 4590  df-tp 4592  df-op 4594  df-uni 4871  df-int 4911  df-iun 4956  df-iin 4957  df-br 5108  df-opab 5172  df-mpt 5191  df-tr 5217  df-id 5554  df-eprel 5559  df-po 5567  df-so 5568  df-fr 5612  df-se 5613  df-we 5614  df-xp 5665  df-rel 5666  df-cnv 5667  df-co 5668  df-dm 5669  df-rn 5670  df-res 5671  df-ima 5672  df-pred 6303  df-ord 6364  df-on 6365  df-lim 6366  df-suc 6367  df-iota 6493  df-fun 6539  df-fn 6540  df-f 6541  df-f1 6542  df-fo 6543  df-f1o 6544  df-fv 6545  df-isom 6546  df-riota 7373  df-ov 7419  df-oprab 7420  df-mpo 7421  df-of 7681  df-rpss 7727  df-om 7866  df-1st 7989  df-2nd 7990  df-supp 8162  df-tpos 8227  df-frecs 8283  df-wrecs 8314  df-recs 8363  df-rdg 8402  df-1o 8458  df-2o 8459  df-oadd 8462  df-er 8699  df-map 8831  df-ixp 8908  df-en 8956  df-dom 8957  df-sdom 8958  df-fin 8959  df-fsupp 9335  df-sup 9415  df-oi 9485  df-r1 9749  df-rank 9750  df-scott 9871  df-dju 9909  df-card 9947  df-acn 9950  df-ac 10122  df-pnf 11272  df-mnf 11273  df-xr 11274  df-ltxr 11275  df-le 11276  df-sub 11470  df-neg 11471  df-nn 12261  df-2 12330  df-3 12331  df-4 12332  df-5 12333  df-6 12334  df-7 12335  df-8 12336  df-9 12337  df-n0 12532  df-xnn0 12605  df-z 12619  df-dec 12740  df-uz 12891  df-rp 13045  df-xmul 13167  df-fz 13564  df-fzo 13712  df-seq 14068  df-exp 14128  df-hash 14397  df-word 14581  df-lsw 14630  df-concat 14638  df-s1 14665  df-substr 14711  df-pfx 14743  df-struct 17243  df-sets 17260  df-slot 17278  df-ndx 17290  df-base 17306  df-ress 17327  df-plusg 17359  df-mulr 17360  df-sca 17362  df-vsca 17363  df-ip 17364  df-tset 17365  df-ple 17366  df-ocomp 17367  df-ds 17368  df-hom 17370  df-cco 17371  df-0g 17530  df-gsum 17531  df-prds 17536  df-pws 17538  df-mre 17674  df-mrc 17675  df-mri 17676  df-acs 17677  df-proset 18386  df-drs 18387  df-poset 18405  df-ipo 18620  df-chn 18698  df-mgm 18734  df-sgrp 18825  df-mnd 18841  df-mhm 18895  df-submnd 18896  df-grp 19064  df-minusg 19065  df-sbg 19066  df-mulg 19195  df-subg 19250  df-ghm 19345  df-cntz 19448  df-cmn 19913  df-abl 19914  df-mgp 20278  df-rng 20292  df-ur 20325  df-ring 20378  df-cring 20379  df-oppr 20482  df-dvdsr 20502  df-unit 20503  df-invr 20533  df-nzr 20677  df-subrng 20712  df-subrg 20736  df-drng 20896  df-field 20897  df-sdrg 20957  df-lmod 21050  df-lss 21120  df-lsp 21160  df-lmhm 21210  df-lbs 21263  df-lvec 21291  df-sra 21361  df-rgmod 21362  df-lidl 21399  df-rsp 21400  df-dsmm 21949  df-frlm 21964  df-uvc 22000  df-lindf 22023  df-linds 22024  df-dim 34112  df-fldext 34153  df-extdg 34154
This theorem is used by:  constrext2chnlem  34262
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