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Theorem reapti 8758
Description: Real apartness is tight. Beyond the development of apartness itself, proofs should use apti 8801. (Contributed by Jim Kingdon, 30-Jan-2020.) (New usage is discouraged.)
Assertion
Ref Expression
reapti ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 = 𝐵 ↔ ¬ 𝐴 # 𝐵))

Proof of Theorem reapti
StepHypRef Expression
1 ltnr 8255 . . . . 5 (𝐴 ∈ ℝ → ¬ 𝐴 < 𝐴)
21adantr 276 . . . 4 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ¬ 𝐴 < 𝐴)
3 oridm 764 . . . . . 6 ((𝐴 < 𝐴𝐴 < 𝐴) ↔ 𝐴 < 𝐴)
4 breq2 4092 . . . . . . 7 (𝐴 = 𝐵 → (𝐴 < 𝐴𝐴 < 𝐵))
5 breq1 4091 . . . . . . 7 (𝐴 = 𝐵 → (𝐴 < 𝐴𝐵 < 𝐴))
64, 5orbi12d 800 . . . . . 6 (𝐴 = 𝐵 → ((𝐴 < 𝐴𝐴 < 𝐴) ↔ (𝐴 < 𝐵𝐵 < 𝐴)))
73, 6bitr3id 194 . . . . 5 (𝐴 = 𝐵 → (𝐴 < 𝐴 ↔ (𝐴 < 𝐵𝐵 < 𝐴)))
87notbid 673 . . . 4 (𝐴 = 𝐵 → (¬ 𝐴 < 𝐴 ↔ ¬ (𝐴 < 𝐵𝐵 < 𝐴)))
92, 8syl5ibcom 155 . . 3 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 = 𝐵 → ¬ (𝐴 < 𝐵𝐵 < 𝐴)))
10 reapval 8755 . . . 4 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 # 𝐵 ↔ (𝐴 < 𝐵𝐵 < 𝐴)))
1110notbid 673 . . 3 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (¬ 𝐴 # 𝐵 ↔ ¬ (𝐴 < 𝐵𝐵 < 𝐴)))
129, 11sylibrd 169 . 2 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 = 𝐵 → ¬ 𝐴 # 𝐵))
13 axapti 8249 . . . 4 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ ¬ (𝐴 < 𝐵𝐵 < 𝐴)) → 𝐴 = 𝐵)
14133expia 1231 . . 3 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (¬ (𝐴 < 𝐵𝐵 < 𝐴) → 𝐴 = 𝐵))
1511, 14sylbid 150 . 2 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (¬ 𝐴 # 𝐵𝐴 = 𝐵))
1612, 15impbid 129 1 ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 = 𝐵 ↔ ¬ 𝐴 # 𝐵))
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wb 105  wo 715   = wceq 1397  wcel 2202   class class class wbr 4088  cr 8030   < clt 8213   # creap 8753
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-13 2204  ax-14 2205  ax-ext 2213  ax-sep 4207  ax-pow 4264  ax-pr 4299  ax-un 4530  ax-setind 4635  ax-cnex 8122  ax-resscn 8123  ax-pre-ltirr 8143  ax-pre-apti 8146
This theorem depends on definitions:  df-bi 117  df-3an 1006  df-tru 1400  df-fal 1403  df-nf 1509  df-sb 1811  df-eu 2082  df-mo 2083  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-ne 2403  df-nel 2498  df-ral 2515  df-rex 2516  df-rab 2519  df-v 2804  df-dif 3202  df-un 3204  df-in 3206  df-ss 3213  df-pw 3654  df-sn 3675  df-pr 3676  df-op 3678  df-uni 3894  df-br 4089  df-opab 4151  df-xp 4731  df-pnf 8215  df-mnf 8216  df-ltxr 8218  df-reap 8754
This theorem is referenced by:  rimul  8764  apreap  8766  apti  8801
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