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Theorem infeq1 6850
Description: Equality theorem for infimum. (Contributed by AV, 2-Sep-2020.)
Assertion
Ref Expression
infeq1  |-  ( B  =  C  -> inf ( B ,  A ,  R
)  = inf ( C ,  A ,  R
) )

Proof of Theorem infeq1
StepHypRef Expression
1 supeq1 6825 . 2  |-  ( B  =  C  ->  sup ( B ,  A ,  `' R )  =  sup ( C ,  A ,  `' R ) )
2 df-inf 6824 . 2  |- inf ( B ,  A ,  R
)  =  sup ( B ,  A ,  `' R )
3 df-inf 6824 . 2  |- inf ( C ,  A ,  R
)  =  sup ( C ,  A ,  `' R )
41, 2, 33eqtr4g 2172 1  |-  ( B  =  C  -> inf ( B ,  A ,  R
)  = inf ( C ,  A ,  R
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1314   `'ccnv 4498   supcsup 6821  infcinf 6822
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 681  ax-5 1406  ax-7 1407  ax-gen 1408  ax-ie1 1452  ax-ie2 1453  ax-8 1465  ax-10 1466  ax-11 1467  ax-i12 1468  ax-bndl 1469  ax-4 1470  ax-17 1489  ax-i9 1493  ax-ial 1497  ax-i5r 1498  ax-ext 2097
This theorem depends on definitions:  df-bi 116  df-tru 1317  df-nf 1420  df-sb 1719  df-clab 2102  df-cleq 2108  df-clel 2111  df-nfc 2244  df-ral 2395  df-rex 2396  df-rab 2399  df-uni 3703  df-sup 6823  df-inf 6824
This theorem is referenced by:  infeq1d  6851  infeq1i  6852
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