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Theorem infeq3 7011
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 4800 . . 3  |-  ( R  =  S  ->  `' R  =  `' S
)
2 supeq3 6986 . . 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 6981 . 2  |- inf ( A ,  B ,  R
)  =  sup ( A ,  B ,  `' R )
5 df-inf 6981 . 2  |- inf ( A ,  B ,  S
)  =  sup ( A ,  B ,  `' S )
63, 4, 53eqtr4g 2235 1  |-  ( R  =  S  -> inf ( A ,  B ,  R
)  = inf ( A ,  B ,  S
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1353   `'ccnv 4624   supcsup 6978  infcinf 6979
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 614  ax-in2 615  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159
This theorem depends on definitions:  df-bi 117  df-tru 1356  df-nf 1461  df-sb 1763  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460  df-rex 2461  df-rab 2464  df-in 3135  df-ss 3142  df-uni 3810  df-br 4003  df-opab 4064  df-cnv 4633  df-sup 6980  df-inf 6981
This theorem is referenced by: (None)
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