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Theorem infeq2 7080
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 7055 . 2  |-  ( B  =  C  ->  sup ( A ,  B ,  `' R )  =  sup ( A ,  C ,  `' R ) )
2 df-inf 7051 . 2  |- inf ( A ,  B ,  R
)  =  sup ( A ,  B ,  `' R )
3 df-inf 7051 . 2  |- inf ( A ,  C ,  R
)  =  sup ( A ,  C ,  `' R )
41, 2, 33eqtr4g 2254 1  |-  ( B  =  C  -> inf ( A ,  B ,  R
)  = inf ( A ,  C ,  R
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    = wceq 1364   `'ccnv 4662   supcsup 7048  infcinf 7049
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 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178
This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ral 2480  df-rex 2481  df-rab 2484  df-uni 3840  df-sup 7050  df-inf 7051
This theorem is referenced by: (None)
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