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Theorem infssd 32505
Description: Inequality deduction for infimum of a subset. (Contributed by AV, 4-Oct-2020.)
Hypotheses
Ref Expression
infssd.0 (𝜑𝑅 Or 𝐴)
infssd.1 (𝜑𝐶𝐵)
infssd.3 (𝜑 → ∃𝑥𝐴 (∀𝑦𝐶 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦𝐴 (𝑥𝑅𝑦 → ∃𝑧𝐶 𝑧𝑅𝑦)))
infssd.4 (𝜑 → ∃𝑥𝐴 (∀𝑦𝐵 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦𝐴 (𝑥𝑅𝑦 → ∃𝑧𝐵 𝑧𝑅𝑦)))
Assertion
Ref Expression
infssd (𝜑 → ¬ inf(𝐶, 𝐴, 𝑅)𝑅inf(𝐵, 𝐴, 𝑅))
Distinct variable groups:   𝑥,𝑦,𝑧,𝐴   𝑥,𝐵,𝑦,𝑧   𝑥,𝐶,𝑦,𝑧   𝑥,𝑅,𝑦,𝑧   𝜑,𝑧
Allowed substitution hints:   𝜑(𝑥,𝑦)

Proof of Theorem infssd
StepHypRef Expression
1 infssd.0 . . 3 (𝜑𝑅 Or 𝐴)
2 infssd.4 . . 3 (𝜑 → ∃𝑥𝐴 (∀𝑦𝐵 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦𝐴 (𝑥𝑅𝑦 → ∃𝑧𝐵 𝑧𝑅𝑦)))
31, 2infcl 9512 . 2 (𝜑 → inf(𝐵, 𝐴, 𝑅) ∈ 𝐴)
4 infssd.1 . . . . 5 (𝜑𝐶𝐵)
54sseld 3979 . . . 4 (𝜑 → (𝑧𝐶𝑧𝐵))
61, 2inflb 9513 . . . 4 (𝜑 → (𝑧𝐵 → ¬ 𝑧𝑅inf(𝐵, 𝐴, 𝑅)))
75, 6syld 47 . . 3 (𝜑 → (𝑧𝐶 → ¬ 𝑧𝑅inf(𝐵, 𝐴, 𝑅)))
87ralrimiv 3142 . 2 (𝜑 → ∀𝑧𝐶 ¬ 𝑧𝑅inf(𝐵, 𝐴, 𝑅))
9 infssd.3 . . 3 (𝜑 → ∃𝑥𝐴 (∀𝑦𝐶 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦𝐴 (𝑥𝑅𝑦 → ∃𝑧𝐶 𝑧𝑅𝑦)))
101, 9infnlb 9516 . 2 (𝜑 → ((inf(𝐵, 𝐴, 𝑅) ∈ 𝐴 ∧ ∀𝑧𝐶 ¬ 𝑧𝑅inf(𝐵, 𝐴, 𝑅)) → ¬ inf(𝐶, 𝐴, 𝑅)𝑅inf(𝐵, 𝐴, 𝑅)))
113, 8, 10mp2and 698 1 (𝜑 → ¬ inf(𝐶, 𝐴, 𝑅)𝑅inf(𝐵, 𝐴, 𝑅))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 395  wcel 2099  wral 3058  wrex 3067  wss 3947   class class class wbr 5148   Or wor 5589  infcinf 9465
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-10 2130  ax-11 2147  ax-12 2167  ax-ext 2699  ax-sep 5299  ax-nul 5306  ax-pr 5429
This theorem depends on definitions:  df-bi 206  df-an 396  df-or 847  df-3or 1086  df-3an 1087  df-tru 1537  df-fal 1547  df-ex 1775  df-nf 1779  df-sb 2061  df-mo 2530  df-eu 2559  df-clab 2706  df-cleq 2720  df-clel 2806  df-nfc 2881  df-ne 2938  df-ral 3059  df-rex 3068  df-rmo 3373  df-reu 3374  df-rab 3430  df-v 3473  df-sbc 3777  df-dif 3950  df-un 3952  df-in 3954  df-ss 3964  df-nul 4324  df-if 4530  df-sn 4630  df-pr 4632  df-op 4636  df-uni 4909  df-br 5149  df-opab 5211  df-po 5590  df-so 5591  df-cnv 5686  df-iota 6500  df-riota 7376  df-sup 9466  df-inf 9467
This theorem is referenced by:  xrge0infssd  32544
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