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Theorem infeq2 7118
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 7093 . 2  |-  ( B  =  C  ->  sup ( A ,  B ,  `' R )  =  sup ( A ,  C ,  `' R ) )
2 df-inf 7089 . 2  |- inf ( A ,  B ,  R
)  =  sup ( A ,  B ,  `' R )
3 df-inf 7089 . 2  |- inf ( A ,  C ,  R
)  =  sup ( A ,  C ,  `' R )
41, 2, 33eqtr4g 2263 1  |-  ( B  =  C  -> inf ( A ,  B ,  R
)  = inf ( A ,  C ,  R
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1373   `'ccnv 4675   supcsup 7086  infcinf 7087
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 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187
This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-ral 2489  df-rex 2490  df-rab 2493  df-uni 3851  df-sup 7088  df-inf 7089
This theorem is referenced by: (None)
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