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Theorem infsnti 7096
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 7051 . 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 7085 . . 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 7071 . 2  |-  ( ph  ->  sup ( { B } ,  A ,  `' R )  =  B )
61, 5eqtrid 2241 1  |-  ( ph  -> inf ( { B } ,  A ,  R )  =  B )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 104    <-> wb 105    = wceq 1364    e. wcel 2167   {csn 3622   class class class wbr 4033   `'ccnv 4662   supcsup 7048  infcinf 7049
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 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-14 2170  ax-ext 2178  ax-sep 4151  ax-pow 4207  ax-pr 4242
This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1475  df-sb 1777  df-eu 2048  df-mo 2049  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ral 2480  df-rex 2481  df-reu 2482  df-rmo 2483  df-rab 2484  df-v 2765  df-sbc 2990  df-un 3161  df-in 3163  df-ss 3170  df-pw 3607  df-sn 3628  df-pr 3629  df-op 3631  df-uni 3840  df-br 4034  df-opab 4095  df-cnv 4671  df-iota 5219  df-riota 5877  df-sup 7050  df-inf 7051
This theorem is referenced by: (None)
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