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Theorem infsnti 7334
Description: The infimum of a singleton. (Contributed by Jim Kingdon, 19-Dec-2021.)
Hypotheses
Ref Expression
infsnti.ti  |-  ( (
ph  /\  ( u  e.  A  /\  v  e.  A ) )  -> 
( u  =  v  <-> 
( -.  u R v  /\  -.  v R u ) ) )
infsnti.b  |-  ( ph  ->  B  e.  A )
Assertion
Ref Expression
infsnti  |-  ( ph  -> inf ( { B } ,  A ,  R )  =  B )
Distinct variable groups:    u, A, v   
u, B, v    u, R, v    ph, u, v

Proof of Theorem infsnti
StepHypRef Expression
1 df-inf 7289 . 2  |- inf ( { B } ,  A ,  R )  =  sup ( { B } ,  A ,  `' R
)
2 infsnti.ti . . . 4  |-  ( (
ph  /\  ( u  e.  A  /\  v  e.  A ) )  -> 
( u  =  v  <-> 
( -.  u R v  /\  -.  v R u ) ) )
32cnvti 7323 . . 3  |-  ( (
ph  /\  ( u  e.  A  /\  v  e.  A ) )  -> 
( u  =  v  <-> 
( -.  u `' R v  /\  -.  v `' R u ) ) )
4 infsnti.b . . 3  |-  ( ph  ->  B  e.  A )
53, 4supsnti 7309 . 2  |-  ( ph  ->  sup ( { B } ,  A ,  `' R )  =  B )
61, 5eqtrid 2279 1  |-  ( ph  -> inf ( { B } ,  A ,  R )  =  B )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 104    <-> wb 105    = wceq 1398    e. wcel 2205   {csn 3694   class class class wbr 4114   `'ccnv 4753   supcsup 7286  infcinf 7287
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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-14 2208  ax-ext 2216  ax-sep 4233  ax-pow 4292  ax-pr 4327
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2085  df-mo 2086  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ral 2527  df-rex 2528  df-reu 2529  df-rmo 2530  df-rab 2531  df-v 2817  df-sbc 3046  df-un 3218  df-in 3220  df-ss 3227  df-pw 3676  df-sn 3700  df-pr 3701  df-op 3703  df-uni 3920  df-br 4115  df-opab 4177  df-cnv 4762  df-iota 5317  df-riota 6011  df-sup 7288  df-inf 7289
This theorem is referenced by: (None)
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