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Theorem alseueu 17152
Description: "The  ph is  ps " implies that exactly one thing is both  ph and  ps. This is the half of dfalseu2 17151 that drops the universal conjunct; it does not reverse, so  E! x ( ph  /\  ps ) cannot be used in place of an "all some one" statement. (Contributed by David A. Wheeler, 22-Jul-2026.)
Assertion
Ref Expression
alseueu  |-  ( A.E! x ( ph  ->  ps )  ->  E! x
( ph  /\  ps )
)

Proof of Theorem alseueu
StepHypRef Expression
1 dfalseu2 17151 . 2  |-  ( A.E! x ( ph  ->  ps )  <->  ( A. x
( ph  ->  ps )  /\  E! x ( ph  /\ 
ps ) ) )
21simprbi 275 1  |-  ( A.E! x ( ph  ->  ps )  ->  E! x
( ph  /\  ps )
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104   A.wal 1400   E!weu 2086   A.E!walseu 17134
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-5 1500  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-4 1563  ax-17 1579  ax-ial 1587
This theorem depends on definitions:  df-bi 117  df-nf 1514  df-eu 2089  df-alseu 17136
This theorem is referenced by: (None)
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