Theorem cdlemesner 40959

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 5135	. . 3 ⊢ ((𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄)) → 𝑅 ≠ 𝑆)
2	1	3ad2ant3 1151	. 2 ⊢ ((𝐾 ∈ HL ∧ (𝑅 ∈ 𝐴 ∧ 𝑆 ∈ 𝐴) ∧ (𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄))) → 𝑅 ≠ 𝑆)
3	2	necomd 3019	1 ⊢ ((𝐾 ∈ HL ∧ (𝑅 ∈ 𝐴 ∧ 𝑆 ∈ 𝐴) ∧ (𝑅 ≤ (𝑃 ∨ 𝑄) ∧ ¬ 𝑆 ≤ (𝑃 ∨ 𝑄))) → 𝑆 ≠ 𝑅)

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 400   ∧ w3a 1101   = wceq 1567   ∈ wcel 2149   ≠ wne 2964   class class class wbr 5113  ‘cfv 6537  (class class class)co 7411  lecple 17316  joincjn 18366  Atomscatm 39926  HLchlt 40013  LHypclh 40647

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1822  ax-4 1836  ax-5 1937  ax-6 1994  ax-7 2035  ax-8 2151  ax-9 2159  ax-ext 2741

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1103  df-tru 1570  df-fal 1580  df-ex 1807  df-sb 2098  df-clab 2748  df-cleq 2761  df-clel 2844  df-ne 2965  df-rab 3424  df-v 3465  df-dif 3916  df-un 3918  df-ss 3930  df-nul 4295  df-if 4493  df-sn 4595  df-pr 4597  df-op 4601  df-br 5114

This theorem is referenced by:  cdlemeda  40961