Theorem cdlemesner 39706

Description: Part of proof of Lemma E in [Crawley] p. 113. Utility lemma. (Contributed by NM, 13-Nov-2012.)

Hypotheses

Ref	Expression
cdlemesner.l	⊢ ≤ = (le‘𝐾)
cdlemesner.j	⊢ ∨ = (join‘𝐾)
cdlemesner.a	⊢ 𝐴 = (Atoms‘𝐾)
cdlemesner.h	⊢ 𝐻 = (LHyp‘𝐾)

Assertion

Ref	Expression
cdlemesner	⊢ ((𝐾 ∈ HL ∧ (𝑅 ∈ 𝐴 ∧ 𝑆 ∈ 𝐴) ∧ (𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄))) → 𝑆 ≠ 𝑅)

Proof of Theorem cdlemesner

Step	Hyp	Ref	Expression
1		nbrne2 5162	. . 3 ⊢ ((𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄)) → 𝑅 ≠ 𝑆)
2	1	3ad2ant3 1133	. 2 ⊢ ((𝐾 ∈ HL ∧ (𝑅 ∈ 𝐴 ∧ 𝑆 ∈ 𝐴) ∧ (𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄))) → 𝑅 ≠ 𝑆)
3	2	necomd 2991	1 ⊢ ((𝐾 ∈ HL ∧ (𝑅 ∈ 𝐴 ∧ 𝑆 ∈ 𝐴) ∧ (𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄))) → 𝑆 ≠ 𝑅)

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 395   ∧ w3a 1085   = wceq 1534   ∈ wcel 2099   ≠ wne 2935   class class class wbr 5142  ‘cfv 6542  (class class class)co 7414  lecple 17231  joincjn 18294  Atomscatm 38672  HLchlt 38759  LHypclh 39394

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1790  ax-4 1804  ax-5 1906  ax-6 1964  ax-7 2004  ax-8 2101  ax-9 2109  ax-ext 2698

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 847  df-3an 1087  df-tru 1537  df-fal 1547  df-ex 1775  df-sb 2061  df-clab 2705  df-cleq 2719  df-clel 2805  df-ne 2936  df-rab 3428  df-v 3471  df-dif 3947  df-un 3949  df-in 3951  df-ss 3961  df-nul 4319  df-if 4525  df-sn 4625  df-pr 4627  df-op 4631  df-br 5143

This theorem is referenced by:  cdlemeda  39708