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Theorem cvnbtwn 30069
Description: The covers relation implies no in-betweenness. (Contributed by NM, 12-Jun-2004.) (New usage is discouraged.)
Assertion
Ref Expression
cvnbtwn ((𝐴C𝐵C𝐶C ) → (𝐴 𝐵 → ¬ (𝐴𝐶𝐶𝐵)))

Proof of Theorem cvnbtwn
Dummy variable 𝑥 is distinct from all other variables.
StepHypRef Expression
1 cvbr 30065 . . . 4 ((𝐴C𝐵C ) → (𝐴 𝐵 ↔ (𝐴𝐵 ∧ ¬ ∃𝑥C (𝐴𝑥𝑥𝐵))))
2 psseq2 4016 . . . . . . . . 9 (𝑥 = 𝐶 → (𝐴𝑥𝐴𝐶))
3 psseq1 4015 . . . . . . . . 9 (𝑥 = 𝐶 → (𝑥𝐵𝐶𝐵))
42, 3anbi12d 633 . . . . . . . 8 (𝑥 = 𝐶 → ((𝐴𝑥𝑥𝐵) ↔ (𝐴𝐶𝐶𝐵)))
54rspcev 3571 . . . . . . 7 ((𝐶C ∧ (𝐴𝐶𝐶𝐵)) → ∃𝑥C (𝐴𝑥𝑥𝐵))
65ex 416 . . . . . 6 (𝐶C → ((𝐴𝐶𝐶𝐵) → ∃𝑥C (𝐴𝑥𝑥𝐵)))
76con3rr3 158 . . . . 5 (¬ ∃𝑥C (𝐴𝑥𝑥𝐵) → (𝐶C → ¬ (𝐴𝐶𝐶𝐵)))
87adantl 485 . . . 4 ((𝐴𝐵 ∧ ¬ ∃𝑥C (𝐴𝑥𝑥𝐵)) → (𝐶C → ¬ (𝐴𝐶𝐶𝐵)))
91, 8syl6bi 256 . . 3 ((𝐴C𝐵C ) → (𝐴 𝐵 → (𝐶C → ¬ (𝐴𝐶𝐶𝐵))))
109com23 86 . 2 ((𝐴C𝐵C ) → (𝐶C → (𝐴 𝐵 → ¬ (𝐴𝐶𝐶𝐵))))
11103impia 1114 1 ((𝐴C𝐵C𝐶C ) → (𝐴 𝐵 → ¬ (𝐴𝐶𝐶𝐵)))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 399  w3a 1084   = wceq 1538  wcel 2111  wrex 3107  wpss 3882   class class class wbr 5030   C cch 28712   ccv 28747
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2113  ax-9 2121  ax-10 2142  ax-11 2158  ax-12 2175  ax-ext 2770  ax-sep 5167  ax-nul 5174  ax-pr 5295
This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-ex 1782  df-nf 1786  df-sb 2070  df-mo 2598  df-eu 2629  df-clab 2777  df-cleq 2791  df-clel 2870  df-nfc 2938  df-ne 2988  df-ral 3111  df-rex 3112  df-v 3443  df-dif 3884  df-un 3886  df-in 3888  df-ss 3898  df-pss 3900  df-nul 4244  df-if 4426  df-sn 4526  df-pr 4528  df-op 4532  df-br 5031  df-opab 5093  df-cv 30062
This theorem is referenced by:  cvnbtwn2  30070  cvnbtwn3  30071  cvnbtwn4  30072  cvntr  30075
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