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Theorem spsbe 1830
Description: A specialization theorem, mostly the same as Theorem 19.8 of [Margaris] p. 89. (Contributed by NM, 5-Aug-1993.) (Proof rewritten by Jim Kingdon, 29-Dec-2017.)
Assertion
Ref Expression
spsbe  |-  ( [ y  /  x ] ph  ->  E. x ph )

Proof of Theorem spsbe
StepHypRef Expression
1 sb1 1754 . 2  |-  ( [ y  /  x ] ph  ->  E. x ( x  =  y  /\  ph ) )
2 simpr 109 . . 3  |-  ( ( x  =  y  /\  ph )  ->  ph )
32eximi 1588 . 2  |-  ( E. x ( x  =  y  /\  ph )  ->  E. x ph )
41, 3syl 14 1  |-  ( [ y  /  x ] ph  ->  E. x ph )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103   E.wex 1480   [wsb 1750
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1435  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-4 1498  ax-ial 1522
This theorem depends on definitions:  df-bi 116  df-sb 1751
This theorem is referenced by:  sbft  1836
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