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Theorem infeq3 6910
Description: Equality theorem for infimum. (Contributed by AV, 2-Sep-2020.)
Assertion
Ref Expression
infeq3  |-  ( R  =  S  -> inf ( A ,  B ,  R
)  = inf ( A ,  B ,  S
) )

Proof of Theorem infeq3
StepHypRef Expression
1 cnveq 4721 . . 3  |-  ( R  =  S  ->  `' R  =  `' S
)
2 supeq3 6885 . . 3  |-  ( `' R  =  `' S  ->  sup ( A ,  B ,  `' R
)  =  sup ( A ,  B ,  `' S ) )
31, 2syl 14 . 2  |-  ( R  =  S  ->  sup ( A ,  B ,  `' R )  =  sup ( A ,  B ,  `' S ) )
4 df-inf 6880 . 2  |- inf ( A ,  B ,  R
)  =  sup ( A ,  B ,  `' R )
5 df-inf 6880 . 2  |- inf ( A ,  B ,  S
)  =  sup ( A ,  B ,  `' S )
63, 4, 53eqtr4g 2198 1  |-  ( R  =  S  -> inf ( A ,  B ,  R
)  = inf ( A ,  B ,  S
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1332   `'ccnv 4546   supcsup 6877  infcinf 6878
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605  ax-io 699  ax-5 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1483  ax-10 1484  ax-11 1485  ax-i12 1486  ax-bndl 1487  ax-4 1488  ax-17 1507  ax-i9 1511  ax-ial 1515  ax-i5r 1516  ax-ext 2122
This theorem depends on definitions:  df-bi 116  df-tru 1335  df-nf 1438  df-sb 1737  df-clab 2127  df-cleq 2133  df-clel 2136  df-nfc 2271  df-ral 2422  df-rex 2423  df-rab 2426  df-in 3082  df-ss 3089  df-uni 3745  df-br 3938  df-opab 3998  df-cnv 4555  df-sup 6879  df-inf 6880
This theorem is referenced by: (None)
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