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Theorem infeq3 6980
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 4778 . . 3  |-  ( R  =  S  ->  `' R  =  `' S
)
2 supeq3 6955 . . 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 6950 . 2  |- inf ( A ,  B ,  R
)  =  sup ( A ,  B ,  `' R )
5 df-inf 6950 . 2  |- inf ( A ,  B ,  S
)  =  sup ( A ,  B ,  `' S )
63, 4, 53eqtr4g 2224 1  |-  ( R  =  S  -> inf ( A ,  B ,  R
)  = inf ( A ,  B ,  S
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1343   `'ccnv 4603   supcsup 6947  infcinf 6948
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 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147
This theorem depends on definitions:  df-bi 116  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ral 2449  df-rex 2450  df-rab 2453  df-in 3122  df-ss 3129  df-uni 3790  df-br 3983  df-opab 4044  df-cnv 4612  df-sup 6949  df-inf 6950
This theorem is referenced by: (None)
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