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Theorem fldext2chn 34430
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 6908 . . . . . 6 (𝑑 = ∅ → (♯‘𝑑) = (♯‘∅))
32breq2d 5118 . . . . 5 (𝑑 = ∅ → (0 < (♯‘𝑑) ↔ 0 < (♯‘∅)))
4 fveq2 6908 . . . . . . . 8 (𝑑 = ∅ → (lastS‘𝑑) = (lastS‘∅))
54oveq2d 7459 . . . . . . 7 (𝑑 = ∅ → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘∅)))
6 fveq1 6907 . . . . . . . 8 (𝑑 = ∅ → (𝑑‘0) = (∅‘0))
76oveq2d 7459 . . . . . . 7 (𝑑 = ∅ → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s (∅‘0)))
85, 7breq12d 5119 . . . . . 6 (𝑑 = ∅ → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘∅))/FldExt(𝑊 ↾s (∅‘0))))
95, 7oveq12d 7461 . . . . . . . 8 (𝑑 = ∅ → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))))
109eqeq1d 2765 . . . . . . 7 (𝑑 = ∅ → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘∅))[:](𝑊 ↾s (∅‘0))) = (2↑𝑛)))
1110rexbidv 3190 . . . . . 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 6908 . . . . . 6 (𝑑 = 𝑐 → (♯‘𝑑) = (♯‘𝑐))
1514breq2d 5118 . . . . 5 (𝑑 = 𝑐 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑐)))
16 fveq2 6908 . . . . . . . 8 (𝑑 = 𝑐 → (lastS‘𝑑) = (lastS‘𝑐))
1716oveq2d 7459 . . . . . . 7 (𝑑 = 𝑐 → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘𝑐)))
18 fveq1 6907 . . . . . . . 8 (𝑑 = 𝑐 → (𝑑‘0) = (𝑐‘0))
1918oveq2d 7459 . . . . . . 7 (𝑑 = 𝑐 → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s (𝑐‘0)))
2017, 19breq12d 5119 . . . . . 6 (𝑑 = 𝑐 → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘𝑐))/FldExt(𝑊 ↾s (𝑐‘0))))
2117, 19oveq12d 7461 . . . . . . . 8 (𝑑 = 𝑐 → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))))
2221eqeq1d 2765 . . . . . . 7 (𝑑 = 𝑐 → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛)))
2322rexbidv 3190 . . . . . 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 6908 . . . . . 6 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (♯‘𝑑) = (♯‘(𝑐 ++ ⟨“𝑔”⟩)))
2726breq2d 5118 . . . . 5 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (0 < (♯‘𝑑) ↔ 0 < (♯‘(𝑐 ++ ⟨“𝑔”⟩))))
28 fveq2 6908 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (lastS‘𝑑) = (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))
2928oveq2d 7459 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩))))
30 fveq1 6907 . . . . . . . 8 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑑‘0) = ((𝑐 ++ ⟨“𝑔”⟩)‘0))
3130oveq2d 7459 . . . . . . 7 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0)))
3229, 31breq12d 5119 . . . . . 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 7461 . . . . . . . . 9 (𝑑 = (𝑐 ++ ⟨“𝑔”⟩) → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘(𝑐 ++ ⟨“𝑔”⟩)))[:](𝑊 ↾s ((𝑐 ++ ⟨“𝑔”⟩)‘0))))
3433eqeq1d 2765 . . . . . . . 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 3190 . . . . . . 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 7451 . . . . . . . . 9 (𝑛 = 𝑚 → (2↑𝑛) = (2↑𝑚))
3736eqeq2d 2774 . . . . . . . 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 3245 . . . . . . 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 6908 . . . . . 6 (𝑑 = 𝑇 → (♯‘𝑑) = (♯‘𝑇))
4342breq2d 5118 . . . . 5 (𝑑 = 𝑇 → (0 < (♯‘𝑑) ↔ 0 < (♯‘𝑇)))
44 fveq2 6908 . . . . . . . 8 (𝑑 = 𝑇 → (lastS‘𝑑) = (lastS‘𝑇))
4544oveq2d 7459 . . . . . . 7 (𝑑 = 𝑇 → (𝑊 ↾s (lastS‘𝑑)) = (𝑊 ↾s (lastS‘𝑇)))
46 fveq1 6907 . . . . . . . 8 (𝑑 = 𝑇 → (𝑑‘0) = (𝑇‘0))
4746oveq2d 7459 . . . . . . 7 (𝑑 = 𝑇 → (𝑊 ↾s (𝑑‘0)) = (𝑊 ↾s (𝑇‘0)))
4845, 47breq12d 5119 . . . . . 6 (𝑑 = 𝑇 → ((𝑊 ↾s (lastS‘𝑑))/FldExt(𝑊 ↾s (𝑑‘0)) ↔ (𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0))))
4945, 47oveq12d 7461 . . . . . . . 8 (𝑑 = 𝑇 → ((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))))
5049eqeq1d 2765 . . . . . . 7 (𝑑 = 𝑇 → (((𝑊 ↾s (lastS‘𝑑))[:](𝑊 ↾s (𝑑‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛)))
5150rexbidv 3190 . . . . . 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 11337 . . . . . . . 8 0 ∈ ℝ
5655ltnri 11446 . . . . . . 7 ¬ 0 < 0
5756a1i 11 . . . . . 6 (𝜑 → ¬ 0 < 0)
58 hash0 14538 . . . . . . 7 (♯‘∅) = 0
5958breq2i 5114 . . . . . 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 21085 . . . . . . . . . 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 34361 . . . . . . . . 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 18811 . . . . . . . . . . 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 14810 . . . . . . . . . 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 7459 . . . . . . . 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 7458 . . . . . . . . . . . 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 15102 . . . . . . . . . . . 12 ⟨“𝑔”⟩ = (∅ ++ ⟨“𝑔”⟩)
7876, 77eqtr4di 2816 . . . . . . . . . . 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 6910 . . . . . . . . . 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 14786 . . . . . . . . . . 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 2798 . . . . . . . . 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 7459 . . . . . . . 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 5140 . . . . . . 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 7451 . . . . . . . . . 10 (𝑚 = 0 → (2↑𝑚) = (2↑0))
86 2cn 12445 . . . . . . . . . . 11 2 ∈ ℂ
87 exp0 14235 . . . . . . . . . . 11 (2 ∈ ℂ → (2↑0) = 1)
8886, 87ax-mp 5 . . . . . . . . . 10 (2↑0) = 1
8985, 88eqtrdi 2814 . . . . . . . . 9 (𝑚 = 0 → (2↑𝑚) = 1)
9089eqeq2d 2774 . . . . . . . 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 12648 . . . . . . . . 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 7461 . . . . . . . . 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 34362 . . . . . . . . . 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 2798 . . . . . . . 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 3583 . . . . . . 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 2964 . . . . . . . . . . . . 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 14740 . . . . . . . . . . . . . 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 5115 . . . . . . . . . . . . . . . . 17 (𝐸/FldExt𝐹 ↔ (𝑊 ↾s 𝑒)/FldExt(𝑊 ↾s 𝑓))
110107, 108oveq12i 7455 . . . . . . . . . . . . . . . . . 18 (𝐸[:]𝐹) = ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓))
111110eqeq1i 2768 . . . . . . . . . . . . . . . . 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 7451 . . . . . . . . . . . . . . . . . . 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 7451 . . . . . . . . . . . . . . . . . . 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 5119 . . . . . . . . . . . . . . . . 17 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → ((𝑊 ↾s 𝑒)/FldExt(𝑊 ↾s 𝑓) ↔ (𝑊 ↾s 𝑔)/FldExt(𝑊 ↾s (lastS‘𝑐))))
118114, 116oveq12d 7461 . . . . . . . . . . . . . . . . . 18 ((𝑒 = 𝑔 ∧ 𝑓 = (lastS‘𝑐)) → ((𝑊 ↾s 𝑒)[:](𝑊 ↾s 𝑓)) = ((𝑊 ↾s 𝑔)[:](𝑊 ↾s (lastS‘𝑐))))
119118eqeq1d 2765 . . . . . . . . . . . . . . . . 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 5512 . . . . . . . . . . . . 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 14559 . . . . . . . . . . . . . 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 7451 . . . . . . . . . . . . 13 (𝑛 = 𝑜 → (2↑𝑛) = (2↑𝑜))
134133eqeq2d 2774 . . . . . . . . . . . 12 (𝑛 = 𝑜 → (((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑛) ↔ ((𝑊 ↾s (lastS‘𝑐))[:](𝑊 ↾s (𝑐‘0))) = (2↑𝑜)))
135134cbvrexvw 3245 . . . . . . . . . . 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 3174 . . . . . . . . 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 34360 . . . . . . . . 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 7459 . . . . . . . . 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 3174 . . . . . . . 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 14777 . . . . . . . . . . 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 14756 . . . . . . . . . . 11 ((𝑐 ∈ Word (SubDRing‘𝑊) ∧ ⟨“𝑔”⟩ ∈ Word (SubDRing‘𝑊) ∧ 0 < (♯‘𝑐)) → ((𝑐 ++ ⟨“𝑔”⟩)‘0) = (𝑐‘0))
147103, 144, 145, 146syl3anc 1399 . . . . . . . . . 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 7459 . . . . . . . . 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 3174 . . . . . . . 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 5140 . . . . . . 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 7451 . . . . . . . . . 10 (𝑚 = (𝑜 + 1) → (2↑𝑚) = (2↑(𝑜 + 1)))
152151eqeq2d 2774 . . . . . . . . 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 12649 . . . . . . . . . . 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 12698 . . . . . . . . 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 7461 . . . . . . . . . 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 34365 . . . . . . . . . . 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 14316 . . . . . . . . . . . 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 11357 . . . . . . . . . . 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 7461 . . . . . . . . . . . 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 12444 . . . . . . . . . . . . . 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 14333 . . . . . . . . . . . . 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 13428 . . . . . . . . . . . . 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 2798 . . . . . . . . . . 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 14317 . . . . . . . . . . 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 2808 . . . . . . . . . 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 2802 . . . . . . . . 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 3583 . . . . . . . 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 3174 . . . . . . 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 3046 . . . . 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 18824 . . 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 5119 . . 3 (𝜑 → ((𝑊 ↾s (lastS‘𝑇))/FldExt(𝑊 ↾s (𝑇‘0)) ↔ 𝐿/FldExt𝑄))
186183, 184oveq12d 7461 . . . . 5 (𝜑 → ((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (𝐿[:]𝑄))
187186eqeq1d 2765 . . . 4 (𝜑 → (((𝑊 ↾s (lastS‘𝑇))[:](𝑊 ↾s (𝑇‘0))) = (2↑𝑛) ↔ (𝐿[:]𝑄) = (2↑𝑛)))
188187rexbidv 3190 . . 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 1570   ∈ wcel 2147   ≠ wne 2959  ∃wrex 3090  ∅c0 4281   class class class wbr 5106  {copab 5170  ‘cfv 6558  (class class class)co 7443  ℂcc 11225  ℝcr 11226  0cc0 11227  1c1 11228   + caddc 11230   · cmul 11232   < clt 11370  2c2 12424  ℕ0cn0 12633   ·e cxmu 13267  ↑cexp 14231  ♯chash 14501  Word cword 14685  lastSclsw 14734   ++ cconcat 14742  ⟨“cs1 14769   ↾s cress 17437   Chain cchn 18808  Fieldcfield 21011  SubDRingcsdrg 21073  /FldExtcfldext 34340  [:]cextdg 34342
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 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-11 2197  ax-12 2216  ax-ext 2735  ax-rep 5235  ax-sep 5252  ax-nul 5263  ax-pow 5331  ax-pr 5395  ax-un 7775  ax-inf2 9669  ax-ac2 10568  ax-cnex 11283  ax-resscn 11284  ax-1cn 11285  ax-icn 11286  ax-addcl 11287  ax-addrcl 11288  ax-mulcl 11289  ax-mulrcl 11290  ax-mulcom 11291  ax-addass 11292  ax-mulass 11293  ax-distr 11294  ax-i2m1 11295  ax-1ne0 11296  ax-1rid 11297  ax-rnegex 11298  ax-rrecex 11299  ax-cnre 11300  ax-pre-lttri 11301  ax-pre-lttrn 11302  ax-pre-ltadd 11303  ax-pre-mulgt0 11304
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 2102  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2839  df-nfc 2913  df-ne 2960  df-nel 3066  df-ral 3081  df-rex 3091  df-rmo 3369  df-reu 3370  df-rab 3417  df-v 3456  df-sbc 3743  df-csb 3852  df-ss 3901  df-pss 4017  df-dif 4050  df-in 4094  df-un 4154  df-nul 4282  df-if 4486  df-pw 4562  df-sn 4589  df-pr 4591  df-tp 4593  df-op 4839  df-uni 4871  df-int 4911  df-iun 4956  df-iin 4957  df-br 5107  df-opab 5171  df-mpt 5190  df-tr 5216  df-id 5550  df-eprel 5555  df-po 5563  df-so 5564  df-fr 5608  df-se 5609  df-we 5610  df-xp 5661  df-rel 5662  df-cnv 5663  df-co 5664  df-dm 5665  df-rn 5666  df-res 5667  df-ima 5668  df-pred 6322  df-ord 6383  df-on 6384  df-lim 6385  df-suc 6386  df-iota 6512  df-fun 6560  df-fn 6561  df-f 6562  df-f1 6563  df-fo 6564  df-f1o 6565  df-fv 6566  df-isom 6567  df-riota 7400  df-ov 7446  df-oprab 7447  df-mpo 7448  df-of 7717  df-rpss 7763  df-om 7902  df-1st 8025  df-2nd 8026  df-supp 8205  df-tpos 8271  df-frecs 8327  df-wrecs 8358  df-recs 8407  df-rdg 8446  df-1o 8504  df-2o 8505  df-oadd 8508  df-er 8745  df-map 8877  df-ixp 8954  df-en 9002  df-dom 9003  df-sdom 9004  df-fin 9005  df-fsupp 9382  df-sup 9461  df-oi 9531  df-dju 10009  df-card 10047  df-acn 10050  df-ac 10222  df-pnf 11372  df-mnf 11373  df-xr 11374  df-ltxr 11375  df-le 11376  df-sub 11570  df-neg 11571  df-nn 12363  df-2 12432  df-3 12433  df-4 12434  df-5 12435  df-6 12436  df-7 12437  df-8 12438  df-9 12439  df-n0 12634  df-xnn0 12707  df-z 12721  df-dec 12842  df-uz 12993  df-rp 13148  df-xmul 13270  df-fz 13667  df-fzo 13816  df-seq 14172  df-exp 14232  df-hash 14502  df-word 14686  df-lsw 14735  df-concat 14743  df-s1 14770  df-substr 14817  df-pfx 14849  df-struct 17354  df-sets 17371  df-slot 17389  df-ndx 17401  df-base 17417  df-ress 17438  df-plusg 17470  df-mulr 17471  df-sca 17473  df-vsca 17474  df-ip 17475  df-tset 17476  df-ple 17477  df-ocomp 17478  df-ds 17479  df-hom 17481  df-cco 17482  df-0g 17641  df-gsum 17642  df-prds 17647  df-pws 17649  df-mre 17785  df-mrc 17786  df-mri 17787  df-acs 17788  df-proset 18497  df-drs 18498  df-poset 18516  df-ipo 18731  df-chn 18809  df-mgm 18845  df-sgrp 18937  df-mnd 18953  df-mhm 19007  df-submnd 19008  df-grp 19176  df-minusg 19177  df-sbg 19178  df-mulg 19307  df-subg 19362  df-ghm 19457  df-cntz 19561  df-cmn 20026  df-abl 20027  df-mgp 20391  df-rng 20405  df-ur 20438  df-ring 20491  df-cring 20492  df-oppr 20597  df-dvdsr 20617  df-unit 20618  df-invr 20648  df-nzr 20793  df-subrng 20828  df-subrg 20852  df-drng 21012  df-field 21013  df-sdrg 21074  df-lmod 21167  df-lss 21237  df-lsp 21277  df-lmhm 21327  df-lbs 21380  df-lvec 21408  df-sra 21478  df-rgmod 21479  df-lidl 21516  df-rsp 21517  df-dsmm 22068  df-frlm 22083  df-uvc 22119  df-lindf 22142  df-linds 22143  df-dim 34302  df-fldext 34343  df-extdg 34344
This theorem is used by:  constrext2chnlem  34452
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