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Theorem fldext2chn 34403
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 = (𝑊 ↾s 𝑒)
fldext2chn.f 𝐹 = (𝑊 ↾s 𝑓)
fldext2chn.l < = {⟨𝑓, 𝑒⟩ ∣ (𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2)}
fldext2chn.t (𝜑 → 𝑇 ∈ ( < Chain (SubDRing‘𝑊)))
fldext2chn.w (𝜑 → 𝑊 ∈ Field)
fldext2chn.1 (𝜑 → (𝑊 ↾s (𝑇‘0)) = 𝑄)
fldext2chn.2 (𝜑 → (𝑊 ↾s (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 6885 . . . . . 6 (𝑑 = ∅ → (♯‘𝑑) = (♯‘∅))
32breq2d 5114 . . . . 5 (𝑑 = ∅ → (0 < (♯‘𝑑) ↔ 0 < (♯‘∅)))
4 fveq2 6885 . . . . . . . 8 (𝑑 = ∅ → (lastS‘𝑑) = (lastS‘∅))
54oveq2d 7436 . . . . . . 7 (𝑑 = ∅ → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘∅)))
6 fveq1 6884 . . . . . . . 8 (𝑑 = ∅ → (𝑑‘0) = (∅‘0))
76oveq2d 7436 . . . . . . 7 (𝑑 = ∅ → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s (∅‘0)))
85, 7breq12d 5115 . . . . . 6 (𝑑 = ∅ → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘∅))/FldExt(𝑊 ↾s (∅‘0))))
95, 7oveq12d 7438 . . . . . . . 8 (𝑑 = ∅ → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))))
109eqeq1d 2762 . . . . . . 7 (𝑑 = ∅ → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))) = (2↑𝑛)))
1110rexbidv 3186 . . . . . 6 (𝑑 = ∅ → (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))) = (2↑𝑛)))
128, 11anbi12d 644 . . . . 5 (𝑑 = ∅ → (((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊 ↾s (lastS‘∅))/FldExt(𝑊 ↾s (∅‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))) = (2↑𝑛))))
133, 12imbi12d 347 . . . 4 (𝑑 = ∅ → ((0 < (♯‘𝑑) → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘∅) → ((𝑊 ↾s (lastS‘∅))/FldExt(𝑊 ↾s (∅‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))) = (2↑𝑛)))))
14 fveq2 6885 . . . . . 6 (𝑑 = 𝑐 → (♯‘𝑑) = (♯‘𝑐))
1514breq2d 5114 . . . . 5 (𝑑 = 𝑐 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑐)))
16 fveq2 6885 . . . . . . . 8 (𝑑 = 𝑐 → (lastS‘𝑑) = (lastS‘𝑐))
1716oveq2d 7436 . . . . . . 7 (𝑑 = 𝑐 → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘𝑐)))
18 fveq1 6884 . . . . . . . 8 (𝑑 = 𝑐 → (𝑑‘0) = (𝑐‘0))
1918oveq2d 7436 . . . . . . 7 (𝑑 = 𝑐 → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s (𝑐‘0)))
2017, 19breq12d 5115 . . . . . 6 (𝑑 = 𝑐 → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0))))
2117, 19oveq12d 7438 . . . . . . . 8 (𝑑 = 𝑐 → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))))
2221eqeq1d 2762 . . . . . . 7 (𝑑 = 𝑐 → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))
2322rexbidv 3186 . . . . . 6 (𝑑 = 𝑐 → (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))
2420, 23anbi12d 644 . . . . 5 (𝑑 = 𝑐 → (((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛))))
2515, 24imbi12d 347 . . . 4 (𝑑 = 𝑐 → ((0 < (♯‘𝑑) → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))))
26 fveq2 6885 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (♯‘𝑑) = (♯‘(𝑐 ++ ⟨“𝑔”⟩)))
2726breq2d 5114 . . . . 5 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (0 < (♯‘𝑑) ↔ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))))
28 fveq2 6885 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (lastS‘𝑑) = (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))
2928oveq2d 7436 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))))
30 fveq1 6884 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑑‘0) = ((𝑐 ++ ⟨“𝑔”⟩)‘0))
3130oveq2d 7436 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
3229, 31breq12d 5115 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))))
3329, 31oveq12d 7438 . . . . . . . . 9 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))))
3433eqeq1d 2762 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛)))
3534rexbidv 3186 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛)))
36 oveq2 7428 . . . . . . . . 9 (𝑛 = 𝑚 → (2↑𝑛) = (2↑𝑚))
3736eqeq2d 2771 . . . . . . . 8 (𝑛 = 𝑚 → (((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
3837cbvrexvw 3241 . . . . . . 7 (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑛) ↔ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
3935, 38bitrdi 290 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
4032, 39anbi12d 644 . . . . 5 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))))
4127, 40imbi12d 347 . . . 4 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((0 < (♯‘𝑑) → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩)) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))))
42 fveq2 6885 . . . . . 6 (𝑑 = 𝑇 → (♯‘𝑑) = (♯‘𝑇))
4342breq2d 5114 . . . . 5 (𝑑 = 𝑇 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑇)))
44 fveq2 6885 . . . . . . . 8 (𝑑 = 𝑇 → (lastS‘𝑑) = (lastS‘𝑇))
4544oveq2d 7436 . . . . . . 7 (𝑑 = 𝑇 → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘𝑇)))
46 fveq1 6884 . . . . . . . 8 (𝑑 = 𝑇 → (𝑑‘0) = (𝑇‘0))
4746oveq2d 7436 . . . . . . 7 (𝑑 = 𝑇 → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s (𝑇‘0)))
4845, 47breq12d 5115 . . . . . 6 (𝑑 = 𝑇 → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0))))
4945, 47oveq12d 7438 . . . . . . . 8 (𝑑 = 𝑇 → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))))
5049eqeq1d 2762 . . . . . . 7 (𝑑 = 𝑇 → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛)))
5150rexbidv 3186 . . . . . 6 (𝑑 = 𝑇 → (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛)))
5248, 51anbi12d 644 . . . . 5 (𝑑 = 𝑇 → (((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛)) ↔ ((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛))))
5343, 52imbi12d 347 . . . 4 (𝑑 = 𝑇 → ((0 < (♯‘𝑑) → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛))) ↔ (0 < (♯‘𝑇) → ((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛)))))
54 fldext2chn.t . . . 4 (𝜑 → 𝑇 ∈ ( < Chain (SubDRing‘𝑊)))
55 0re 11311 . . . . . . . 8 0 ∈ ℝ
5655ltnri 11420 . . . . . . 7 ¬ 0 < 0
5756a1i 11 . . . . . 6 (𝜑 → ¬ 0 < 0)
58 hash0 14512 . . . . . . 7 (♯‘∅) = 0
5958breq2i 5110 . . . . . 6 (0 < (♯‘∅) ↔ 0 < 0)
6057, 59sylnibr 332 . . . . 5 (𝜑 → ¬ 0 < (♯‘∅))
6160pm2.21d 122 . . . 4 (𝜑 → (0 < (♯‘∅) → ((𝑊 ↾s (lastS‘∅))/FldExt(𝑊 ↾s (∅‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))) = (2↑𝑛))))
62 fldext2chn.w . . . . . . . . . . 11 (𝜑 → 𝑊 ∈ Field)
6362ad6antr 749 . . . . . . . . . 10 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑊 ∈ Field)
64 simp-5r 798 . . . . . . . . . 10 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑔 ∈ (SubDRing‘𝑊))
65 fldsdrgfld 21056 . . . . . . . . . 10 ((𝑊 ∈ Field ∧ 𝑔 ∈ (SubDRing‘𝑊)) → (𝑊 ↾s 𝑔) ∈ Field)
6663, 64, 65syl2anc 596 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊 ↾s 𝑔) ∈ Field)
67 fldextid 34334 . . . . . . . . 9 ((𝑊 ↾s 𝑔) ∈ Field → (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s 𝑔))
6866, 67syl 18 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s 𝑔))
69 simp-5r 798 . . . . . . . . . . . 12 ((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) → 𝑐 ∈ ( < Chain (SubDRing‘𝑊)))
7069chnwrd 18783 . . . . . . . . . . 11 ((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) → 𝑐 ∈ Word (SubDRing‘𝑊))
7170adantr 486 . . . . . . . . . 10 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑐 ∈ Word (SubDRing‘𝑊))
72 lswccats1 14783 . . . . . . . . . 10 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ 𝑔 ∈ (SubDRing‘𝑊)) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
7371, 64, 72syl2anc 596 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
7473oveq2d 7436 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))) = (𝑊 ↾s 𝑔))
75 simpr 490 . . . . . . . . . . . . 13 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 𝑐 = ∅)
7675oveq1d 7435 . . . . . . . . . . . 12 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑐 ++ ⟨“𝑔”⟩) = (∅ ++ ⟨“𝑔”⟩))
77 s0s1 15074 . . . . . . . . . . . 12 ⟨“𝑔”⟩ = (∅ ++ ⟨“𝑔”⟩)
7876, 77eqtr4di 2813 . . . . . . . . . . 11 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑐 ++ ⟨“𝑔”⟩) = ⟨“𝑔”⟩)
7978fveq1d 6887 . . . . . . . . . 10 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (⟨“𝑔”⟩‘0))
80 s1fv 14759 . . . . . . . . . . 11 (𝑔 ∈ (SubDRing‘𝑊) → (⟨“𝑔”⟩‘0) = 𝑔)
8164, 80syl 18 . . . . . . . . . 10 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (⟨“𝑔”⟩‘0) = 𝑔)
8279, 81eqtrd 2795 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = 𝑔)
8382oveq2d 7436 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) = (𝑊 ↾s 𝑔))
8468, 74, 833brtr4d 5136 . . . . . . 7 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
85 oveq2 7428 . . . . . . . . . 10 (𝑚 = 0 → (2↑𝑚) = (2↑0))
86 2cn 12419 . . . . . . . . . . 11 2 ∈ ℂ
87 exp0 14209 . . . . . . . . . . 11 (2 ∈ ℂ → (2↑0) = 1)
8886, 87ax-mp 5 . . . . . . . . . 10 (2↑0) = 1
8985, 88eqtrdi 2811 . . . . . . . . 9 (𝑚 = 0 → (2↑𝑚) = 1)
9089eqeq2d 2771 . . . . . . . 8 (𝑚 = 0 → (((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚) ↔ ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = 1))
91 0nn0 12622 . . . . . . . . 9 0 ∈ ℕ0
9291a1i 11 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → 0 ∈ ℕ0)
9374, 83oveq12d 7438 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = ((𝑊 ↾s 𝑔)[:](𝑊 ↾s 𝑔)))
94 extdgid 34335 . . . . . . . . . 10 ((𝑊 ↾s 𝑔) ∈ Field → ((𝑊 ↾s 𝑔)[:](𝑊 ↾s 𝑔)) = 1)
9566, 94syl 18 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊 ↾s 𝑔)[:](𝑊 ↾s 𝑔)) = 1)
9693, 95eqtrd 2795 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = 1)
9790, 92, 96rspcedvdw 3579 . . . . . . 7 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
9884, 97jca 521 . . . . . 6 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 = ∅) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
99 simp-6r 800 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔))
100 simpllr 788 . . . . . . . . . . . . . 14 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 𝑐 ≠ ∅)
101100neneqd 2960 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ¬ 𝑐 = ∅)
10299, 101orcnd 892 . . . . . . . . . . . 12 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (lastS‘𝑐) < 𝑔)
10370ad3antrrr 743 . . . . . . . . . . . . . 14 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 𝑐 ∈ Word (SubDRing‘𝑊))
104 lswcl 14714 . . . . . . . . . . . . . 14 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ 𝑐 ≠ ∅) → (lastS‘𝑐) ∈ (SubDRing‘𝑊))
105103, 100, 104syl2anc 596 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (lastS‘𝑐) ∈ (SubDRing‘𝑊))
106 simp-7r 802 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 𝑔 ∈ (SubDRing‘𝑊))
107 fldext2chn.e . . . . . . . . . . . . . . . . . 18 𝐸 = (𝑊 ↾s 𝑒)
108 fldext2chn.f . . . . . . . . . . . . . . . . . 18 𝐹 = (𝑊 ↾s 𝑓)
109107, 108breq12i 5111 . . . . . . . . . . . . . . . . 17 (𝐸/FldExt𝐹 ↔ (𝑊 ↾s 𝑒)/FldExt(𝑊 ↾s 𝑓))
110107, 108oveq12i 7432 . . . . . . . . . . . . . . . . . 18 (𝐸[:]𝐹) = ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓))
111110eqeq1i 2765 . . . . . . . . . . . . . . . . 17 ((𝐸[:]𝐹) = 2 ↔ ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓)) = 2)
112109, 111anbi12i 640 . . . . . . . . . . . . . . . 16 ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊 ↾s 𝑒)/FldExt(𝑊 ↾s 𝑓) ∧ ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓)) = 2))
113 oveq2 7428 . . . . . . . . . . . . . . . . . . 19 (𝑒 = 𝑔 → (𝑊 ↾s 𝑒) = (𝑊 ↾s 𝑔))
114113adantr 486 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → (𝑊 ↾s 𝑒) = (𝑊 ↾s 𝑔))
115 oveq2 7428 . . . . . . . . . . . . . . . . . . 19 (𝑓 = (lastS‘𝑐) → (𝑊 ↾s 𝑓) = (𝑊 ↾s (lastS‘𝑐)))
116115adantl 487 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → (𝑊 ↾s 𝑓) = (𝑊 ↾s (lastS‘𝑐)))
117114, 116breq12d 5115 . . . . . . . . . . . . . . . . 17 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → ((𝑊 ↾s 𝑒)/FldExt(𝑊 ↾s 𝑓) ↔ (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐))))
118114, 116oveq12d 7438 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓)) = ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))))
119118eqeq1d 2762 . . . . . . . . . . . . . . . . 17 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → (((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓)) = 2 ↔ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2))
120117, 119anbi12d 644 . . . . . . . . . . . . . . . 16 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → (((𝑊 ↾s 𝑒)/FldExt(𝑊 ↾s 𝑓) ∧ ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓)) = 2) ↔ ((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2)))
121112, 120bitrid 286 . . . . . . . . . . . . . . 15 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2)))
122121ancoms 464 . . . . . . . . . . . . . 14 ((𝑓 = (lastS‘𝑐) ∧ 𝑒 = 𝑔) → ((𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2) ↔ ((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2)))
123 fldext2chn.l . . . . . . . . . . . . . 14 < = {⟨𝑓, 𝑒⟩ ∣ (𝐸/FldExt𝐹 ∧ (𝐸[:]𝐹) = 2)}
124122, 123brabga 5507 . . . . . . . . . . . . 13 (((lastS‘𝑐) ∈ (SubDRing‘𝑊) ∧ 𝑔 ∈ (SubDRing‘𝑊)) → ((lastS‘𝑐) < 𝑔 ↔ ((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2)))
125105, 106, 124syl2anc 596 . . . . . . . . . . . 12 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((lastS‘𝑐) < 𝑔 ↔ ((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2)))
126102, 125mpbid 235 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2))
127126simpld 500 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)))
128 hashgt0 14533 . . . . . . . . . . . . . 14 ((𝑐 ∈ ( < Chain (SubDRing‘𝑊)) ∧ 𝑐 ≠ ∅) → 0 < (♯‘𝑐))
12969, 128sylan 592 . . . . . . . . . . . . 13 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → 0 < (♯‘𝑐))
130 simpllr 788 . . . . . . . . . . . . 13 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛))))
131129, 130mpd 16 . . . . . . . . . . . 12 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))
132131simprd 501 . . . . . . . . . . 11 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛))
133 oveq2 7428 . . . . . . . . . . . . 13 (𝑛 = 𝑜 → (2↑𝑛) = (2↑𝑜))
134133eqeq2d 2771 . . . . . . . . . . . 12 (𝑛 = 𝑜 → (((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)))
135134cbvrexvw 3241 . . . . . . . . . . 11 (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛) ↔ ∃𝑜 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜))
136132, 135sylib 221 . . . . . . . . . 10 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ∃𝑜 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜))
137127, 136r19.29a 3170 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)))
138131simpld 500 . . . . . . . . 9 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)))
139 fldexttr 34333 . . . . . . . . 9 (((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ (𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0))) → (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (𝑐‘0)))
140137, 138, 139syl2anc 596 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (𝑐‘0)))
141103, 106, 72syl2anc 596 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (lastS‘(𝑐 ++ ⟨“𝑔”⟩)) = 𝑔)
142141oveq2d 7436 . . . . . . . . 9 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))) = (𝑊 ↾s 𝑔))
143142, 136r19.29a 3170 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))) = (𝑊 ↾s 𝑔))
144106s1cld 14751 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ⟨“𝑔”⟩ ∈ Word (SubDRing‘𝑊))
145129ad2antrr 739 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 0 < (♯‘𝑐))
146 ccatfv0 14730 . . . . . . . . . . 11 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ ⟨“𝑔”⟩ ∈ Word (SubDRing‘𝑊) ∧ 0 < (♯‘𝑐)) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (𝑐‘0))
147103, 144, 145, 146syl3anc 1398 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (𝑐‘0))
148147oveq2d 7436 . . . . . . . . 9 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) = (𝑊 ↾s (𝑐‘0)))
149148, 136r19.29a 3170 . . . . . . . 8 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) = (𝑊 ↾s (𝑐‘0)))
150140, 143, 1493brtr4d 5136 . . . . . . 7 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
151 oveq2 7428 . . . . . . . . . 10 (𝑚 = (𝑜 + 1) → (2↑𝑚) = (2↑(𝑜 + 1)))
152151eqeq2d 2771 . . . . . . . . 9 (𝑚 = (𝑜 + 1) → (((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚) ↔ ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑(𝑜 + 1))))
153 simplr 781 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 𝑜 ∈ ℕ0)
154 1nn0 12623 . . . . . . . . . . 11 1 ∈ ℕ0
155154a1i 11 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 1 ∈ ℕ0)
156153, 155nn0addcld 12672 . . . . . . . . 9 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (𝑜 + 1) ∈ ℕ0)
157142, 148oveq12d 7438 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (𝑐‘0))))
158138ad2antrr 739 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)))
159 extdgmul 34338 . . . . . . . . . . 11 (((𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐)) ∧ (𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0))) → ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (𝑐‘0))) = (((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) ·e ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0)))))
160127, 158, 159syl2anc 596 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (𝑐‘0))) = (((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) ·e ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0)))))
16186a1i 11 . . . . . . . . . . . 12 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 2 ∈ ℂ)
162161, 153expcld 14290 . . . . . . . . . . . 12 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (2↑𝑜) ∈ ℂ)
163161, 162mulcomd 11331 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (2 · (2↑𝑜)) = ((2↑𝑜) · 2))
164126simprd 501 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) = 2)
165 simpr 490 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜))
166164, 165oveq12d 7438 . . . . . . . . . . . 12 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) ·e ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0)))) = (2 ·e (2↑𝑜)))
167 2re 12418 . . . . . . . . . . . . . 14 2 ∈ ℝ
168167a1i 11 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → 2 ∈ ℝ)
169168, 153reexpcld 14307 . . . . . . . . . . . . 13 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (2↑𝑜) ∈ ℝ)
170 rexmul 13402 . . . . . . . . . . . . 13 ((2 ∈ ℝ ∧ (2↑𝑜) ∈ ℝ) → (2 ·e (2↑𝑜)) = (2 · (2↑𝑜)))
171168, 169, 170syl2anc 596 . . . . . . . . . . . 12 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (2 ·e (2↑𝑜)) = (2 · (2↑𝑜)))
172166, 171eqtrd 2795 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) ·e ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0)))) = (2 · (2↑𝑜)))
173161, 153expp1d 14291 . . . . . . . . . . 11 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (2↑(𝑜 + 1)) = ((2↑𝑜) · 2))
174163, 172, 1733eqtr4d 2805 . . . . . . . . . 10 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → (((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))) ·e ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0)))) = (2↑(𝑜 + 1)))
175157, 160, 1743eqtrd 2799 . . . . . . . . 9 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑(𝑜 + 1)))
176152, 156, 175rspcedvdw 3579 . . . . . . . 8 (((((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) ∧ 𝑜 ∈ ℕ0) ∧ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)) → ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
177176, 136r19.29a 3170 . . . . . . 7 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))
178150, 177jca 521 . . . . . 6 (((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) ∧ 𝑐 ≠ ∅) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
17998, 178pm2.61dane 3042 . . . . 5 ((((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) ∧ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚)))
180179ex 418 . . . 4 (((((𝜑 ∧ 𝑐 ∈ ( < Chain (SubDRing‘𝑊))) ∧ 𝑔 ∈ (SubDRing‘𝑊)) ∧ (𝑐 = ∅ ∨ (lastS‘𝑐) < 𝑔)) ∧ (0 < (♯‘𝑐) → ((𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))) → (0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩)) → ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))/FldExt(𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)) ∧ ∃𝑚 ∈ ℕ0 ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))) = (2↑𝑚))))
18113, 25, 41, 53, 54, 61, 180chnind 18796 . . 3 (𝜑 → (0 < (♯‘𝑇) → ((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛))))
1821, 181mpd 16 . 2 (𝜑 → ((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛)))
183 fldext2chn.2 . . . 4 (𝜑 → (𝑊 ↾s (lastS‘𝑇)) = 𝐿)
184 fldext2chn.1 . . . 4 (𝜑 → (𝑊 ↾s (𝑇‘0)) = 𝑄)
185183, 184breq12d 5115 . . 3 (𝜑 → ((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ↔ 𝐿/FldExt𝑄))
186183, 184oveq12d 7438 . . . . 5 (𝜑 → ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (𝐿[:]𝑄))
187186eqeq1d 2762 . . . 4 (𝜑 → (((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛) ↔ (𝐿[:]𝑄) = (2↑𝑛)))
188187rexbidv 3186 . . 3 (𝜑 → (∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛) ↔ ∃𝑛 ∈ ℕ0 (𝐿[:]𝑄) = (2↑𝑛)))
189185, 188anbi12d 644 . 2 (𝜑 → (((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ∧ ∃𝑛 ∈ ℕ0 ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (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 1569   ∈ wcel 2144   ≠ wne 2955  ∃wrex 3086  ∅c0 4278   class class class wbr 5102  {copab 5166  ‘cfv 6538  (class class class)co 7420  ℂcc 11199  ℝcr 11200  0cc0 11201  1c1 11202   + caddc 11204   · cmul 11206   < clt 11344  2c2 12398  ℕ0cn0 12607   ·e cxmu 13241  ↑cexp 14205  ♯chash 14475  Word cword 14659  lastSclsw 14708   ++ cconcat 14716  ⟨“cs1 14743   ↾s cress 17409   Chain cchn 18780  Fieldcfield 20982  SubDRingcsdrg 21044  /FldExtcfldext 34313  [:]cextdg 34315
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-8 2146  ax-9 2154  ax-10 2177  ax-11 2193  ax-12 2212  ax-ext 2732  ax-rep 5231  ax-sep 5248  ax-nul 5259  ax-pow 5326  ax-pr 5390  ax-un 7751  ax-reg 9587  ax-inf2 9643  ax-ac2 10542  ax-cnex 11257  ax-resscn 11258  ax-1cn 11259  ax-icn 11260  ax-addcl 11261  ax-addrcl 11262  ax-mulcl 11263  ax-mulrcl 11264  ax-mulcom 11265  ax-addass 11266  ax-mulass 11267  ax-distr 11268  ax-i2m1 11269  ax-1ne0 11270  ax-1rid 11271  ax-rnegex 11272  ax-rrecex 11273  ax-cnre 11274  ax-pre-lttri 11275  ax-pre-lttrn 11276  ax-pre-ltadd 11277  ax-pre-mulgt0 11278
This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3or 1104  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-nf 1816  df-sb 2099  df-mo 2564  df-eu 2594  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ne 2956  df-nel 3062  df-ral 3077  df-rex 3087  df-rmo 3365  df-reu 3366  df-rab 3413  df-v 3452  df-sbc 3739  df-csb 3847  df-ss 3896  df-pss 4014  df-dif 4047  df-in 4091  df-un 4151  df-nul 4279  df-if 4482  df-pw 4558  df-sn 4584  df-pr 4586  df-tp 4588  df-op 4590  df-uni 4867  df-int 4907  df-iun 4952  df-iin 4953  df-br 5103  df-opab 5167  df-mpt 5186  df-tr 5212  df-id 5545  df-eprel 5550  df-po 5558  df-so 5559  df-fr 5603  df-se 5604  df-we 5605  df-xp 5656  df-rel 5657  df-cnv 5658  df-co 5659  df-dm 5660  df-rn 5661  df-res 5662  df-ima 5663  df-pred 6304  df-ord 6365  df-on 6366  df-lim 6367  df-suc 6368  df-iota 6494  df-fun 6540  df-fn 6541  df-f 6542  df-f1 6543  df-fo 6544  df-f1o 6545  df-fv 6546  df-isom 6547  df-riota 7377  df-ov 7423  df-oprab 7424  df-mpo 7425  df-of 7693  df-rpss 7739  df-om 7878  df-1st 8001  df-2nd 8002  df-supp 8178  df-tpos 8244  df-frecs 8300  df-wrecs 8331  df-recs 8380  df-rdg 8419  df-1o 8477  df-2o 8478  df-oadd 8481  df-er 8718  df-map 8850  df-ixp 8927  df-en 8975  df-dom 8976  df-sdom 8977  df-fin 8978  df-fsupp 9355  df-sup 9435  df-oi 9505  df-r1 9769  df-rank 9770  df-scott 9930  df-dju 9983  df-card 10021  df-acn 10024  df-ac 10196  df-pnf 11346  df-mnf 11347  df-xr 11348  df-ltxr 11349  df-le 11350  df-sub 11544  df-neg 11545  df-nn 12337  df-2 12406  df-3 12407  df-4 12408  df-5 12409  df-6 12410  df-7 12411  df-8 12412  df-9 12413  df-n0 12608  df-xnn0 12681  df-z 12695  df-dec 12816  df-uz 12967  df-rp 13122  df-xmul 13244  df-fz 13641  df-fzo 13790  df-seq 14146  df-exp 14206  df-hash 14476  df-word 14660  df-lsw 14709  df-concat 14717  df-s1 14744  df-substr 14790  df-pfx 14822  df-struct 17326  df-sets 17343  df-slot 17361  df-ndx 17373  df-base 17389  df-ress 17410  df-plusg 17442  df-mulr 17443  df-sca 17445  df-vsca 17446  df-ip 17447  df-tset 17448  df-ple 17449  df-ocomp 17450  df-ds 17451  df-hom 17453  df-cco 17454  df-0g 17613  df-gsum 17614  df-prds 17619  df-pws 17621  df-mre 17757  df-mrc 17758  df-mri 17759  df-acs 17760  df-proset 18469  df-drs 18470  df-poset 18488  df-ipo 18703  df-chn 18781  df-mgm 18817  df-sgrp 18909  df-mnd 18925  df-mhm 18979  df-submnd 18980  df-grp 19148  df-minusg 19149  df-sbg 19150  df-mulg 19279  df-subg 19334  df-ghm 19429  df-cntz 19532  df-cmn 19997  df-abl 19998  df-mgp 20362  df-rng 20376  df-ur 20409  df-ring 20462  df-cring 20463  df-oppr 20568  df-dvdsr 20588  df-unit 20589  df-invr 20619  df-nzr 20764  df-subrng 20799  df-subrg 20823  df-drng 20983  df-field 20984  df-sdrg 21045  df-lmod 21138  df-lss 21208  df-lsp 21248  df-lmhm 21298  df-lbs 21351  df-lvec 21379  df-sra 21449  df-rgmod 21450  df-lidl 21487  df-rsp 21488  df-dsmm 22039  df-frlm 22054  df-uvc 22090  df-lindf 22113  df-linds 22114  df-dim 34275  df-fldext 34316  df-extdg 34317
This theorem is used by:  constrext2chnlem  34425
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