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Theorem infeq2 7013
Description: Equality theorem for infimum. (Contributed by AV, 2-Sep-2020.)
Assertion
Ref Expression
infeq2  |-  ( B  =  C  -> inf ( A ,  B ,  R
)  = inf ( A ,  C ,  R
) )

Proof of Theorem infeq2
StepHypRef Expression
1 supeq2 6988 . 2  |-  ( B  =  C  ->  sup ( A ,  B ,  `' R )  =  sup ( A ,  C ,  `' R ) )
2 df-inf 6984 . 2  |- inf ( A ,  B ,  R
)  =  sup ( A ,  B ,  `' R )
3 df-inf 6984 . 2  |- inf ( A ,  C ,  R
)  =  sup ( A ,  C ,  `' R )
41, 2, 33eqtr4g 2235 1  |-  ( B  =  C  -> inf ( A ,  B ,  R
)  = inf ( A ,  C ,  R
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1353   `'ccnv 4626   supcsup 6981  infcinf 6982
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-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-uni 3811  df-sup 6983  df-inf 6984
This theorem is referenced by: (None)
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