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Theorem suprubex 8970
Description: A member of a nonempty bounded set of reals is less than or equal to the set's upper bound. (Contributed by Jim Kingdon, 18-Jan-2022.)
Hypotheses
Ref Expression
suprubex.ex  |-  ( ph  ->  E. x  e.  RR  ( A. y  e.  A  -.  x  <  y  /\  A. y  e.  RR  (
y  <  x  ->  E. z  e.  A  y  <  z ) ) )
suprubex.ss  |-  ( ph  ->  A  C_  RR )
suprubex.b  |-  ( ph  ->  B  e.  A )
Assertion
Ref Expression
suprubex  |-  ( ph  ->  B  <_  sup ( A ,  RR ,  <  ) )
Distinct variable groups:    x, A, y, z    ph, x
Allowed substitution hints:    ph( y, z)    B( x, y, z)

Proof of Theorem suprubex
Dummy variables  f  g are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 suprubex.ss . . 3  |-  ( ph  ->  A  C_  RR )
2 suprubex.b . . 3  |-  ( ph  ->  B  e.  A )
31, 2sseldd 3180 . 2  |-  ( ph  ->  B  e.  RR )
4 lttri3 8099 . . . 4  |-  ( ( f  e.  RR  /\  g  e.  RR )  ->  ( f  =  g  <-> 
( -.  f  < 
g  /\  -.  g  <  f ) ) )
54adantl 277 . . 3  |-  ( (
ph  /\  ( f  e.  RR  /\  g  e.  RR ) )  -> 
( f  =  g  <-> 
( -.  f  < 
g  /\  -.  g  <  f ) ) )
6 suprubex.ex . . 3  |-  ( ph  ->  E. x  e.  RR  ( A. y  e.  A  -.  x  <  y  /\  A. y  e.  RR  (
y  <  x  ->  E. z  e.  A  y  <  z ) ) )
75, 6supclti 7057 . 2  |-  ( ph  ->  sup ( A ,  RR ,  <  )  e.  RR )
85, 6supubti 7058 . . 3  |-  ( ph  ->  ( B  e.  A  ->  -.  sup ( A ,  RR ,  <  )  <  B ) )
92, 8mpd 13 . 2  |-  ( ph  ->  -.  sup ( A ,  RR ,  <  )  <  B )
103, 7, 9nltled 8140 1  |-  ( ph  ->  B  <_  sup ( A ,  RR ,  <  ) )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 104    <-> wb 105    e. wcel 2164   A.wral 2472   E.wrex 2473    C_ wss 3153   class class class wbr 4029   supcsup 7041   RRcr 7871    < clt 8054    <_ cle 8055
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 615  ax-in2 616  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-13 2166  ax-14 2167  ax-ext 2175  ax-sep 4147  ax-pow 4203  ax-pr 4238  ax-un 4464  ax-setind 4569  ax-cnex 7963  ax-resscn 7964  ax-pre-ltirr 7984  ax-pre-apti 7987
This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1472  df-sb 1774  df-eu 2045  df-mo 2046  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-ne 2365  df-nel 2460  df-ral 2477  df-rex 2478  df-reu 2479  df-rmo 2480  df-rab 2481  df-v 2762  df-sbc 2986  df-dif 3155  df-un 3157  df-in 3159  df-ss 3166  df-pw 3603  df-sn 3624  df-pr 3625  df-op 3627  df-uni 3836  df-br 4030  df-opab 4091  df-xp 4665  df-cnv 4667  df-iota 5215  df-riota 5873  df-sup 7043  df-pnf 8056  df-mnf 8057  df-xr 8058  df-ltxr 8059  df-le 8060
This theorem is referenced by:  suprzclex  9415
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