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Theorem prarloclem 6657
 Description: A special case of Lemma 6.16 from [BauerTaylor], p. 32. Given evenly spaced rational numbers from 𝐴 to 𝐴 +Q (𝑁 ·Q 𝑃) (which are in the lower and upper cuts, respectively, of a real number), there are a pair of numbers, two positions apart in the even spacing, which straddle the cut. (Contributed by Jim Kingdon, 22-Oct-2019.)
Assertion
Ref Expression
prarloclem (((⟨𝐿, 𝑈⟩ ∈ P𝐴𝐿) ∧ (𝑁N𝑃Q ∧ 1𝑜 <N 𝑁) ∧ (𝐴 +Q ([⟨𝑁, 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → ∃𝑗 ∈ ω ((𝐴 +Q0 ([⟨𝑗, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨(𝑗 +𝑜 2𝑜), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈))
Distinct variable groups:   𝐴,𝑗   𝑗,𝐿   𝑗,𝑁   𝑃,𝑗   𝑈,𝑗

Proof of Theorem prarloclem
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 prarloclem5 6656 . 2 (((⟨𝐿, 𝑈⟩ ∈ P𝐴𝐿) ∧ (𝑁N𝑃Q ∧ 1𝑜 <N 𝑁) ∧ (𝐴 +Q ([⟨𝑁, 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → ∃𝑥 ∈ ω ∃𝑦 ∈ ω ((𝐴 +Q0 ([⟨𝑦, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨((𝑦 +𝑜 2𝑜) +𝑜 𝑥), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈))
2 prarloclem4 6654 . . . 4 (((⟨𝐿, 𝑈⟩ ∈ P𝐴𝐿) ∧ 𝑃Q) → (∃𝑥 ∈ ω ∃𝑦 ∈ ω ((𝐴 +Q0 ([⟨𝑦, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨((𝑦 +𝑜 2𝑜) +𝑜 𝑥), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → ∃𝑗 ∈ ω ((𝐴 +Q0 ([⟨𝑗, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨(𝑗 +𝑜 2𝑜), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈)))
323ad2antr2 1081 . . 3 (((⟨𝐿, 𝑈⟩ ∈ P𝐴𝐿) ∧ (𝑁N𝑃Q ∧ 1𝑜 <N 𝑁)) → (∃𝑥 ∈ ω ∃𝑦 ∈ ω ((𝐴 +Q0 ([⟨𝑦, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨((𝑦 +𝑜 2𝑜) +𝑜 𝑥), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → ∃𝑗 ∈ ω ((𝐴 +Q0 ([⟨𝑗, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨(𝑗 +𝑜 2𝑜), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈)))
433adant3 935 . 2 (((⟨𝐿, 𝑈⟩ ∈ P𝐴𝐿) ∧ (𝑁N𝑃Q ∧ 1𝑜 <N 𝑁) ∧ (𝐴 +Q ([⟨𝑁, 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → (∃𝑥 ∈ ω ∃𝑦 ∈ ω ((𝐴 +Q0 ([⟨𝑦, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨((𝑦 +𝑜 2𝑜) +𝑜 𝑥), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → ∃𝑗 ∈ ω ((𝐴 +Q0 ([⟨𝑗, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨(𝑗 +𝑜 2𝑜), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈)))
51, 4mpd 13 1 (((⟨𝐿, 𝑈⟩ ∈ P𝐴𝐿) ∧ (𝑁N𝑃Q ∧ 1𝑜 <N 𝑁) ∧ (𝐴 +Q ([⟨𝑁, 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈) → ∃𝑗 ∈ ω ((𝐴 +Q0 ([⟨𝑗, 1𝑜⟩] ~Q0 ·Q0 𝑃)) ∈ 𝐿 ∧ (𝐴 +Q ([⟨(𝑗 +𝑜 2𝑜), 1𝑜⟩] ~Q ·Q 𝑃)) ∈ 𝑈))
 Colors of variables: wff set class Syntax hints:   → wi 4   ∧ wa 101   ∧ w3a 896   ∈ wcel 1409  ∃wrex 2324  ⟨cop 3406   class class class wbr 3792  ωcom 4341  (class class class)co 5540  1𝑜c1o 6025  2𝑜c2o 6026   +𝑜 coa 6029  [cec 6135  Ncnpi 6428
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