Users' Mathboxes Mathbox for David A. Wheeler < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >   Mathboxes  >  ralsmd Unicode version

Theorem ralsmd 17138
Description: Deduction rule: Given "all some" applied to a class, the class is inhabited. This is stronger than ralsn0d 17137, which only concludes that the class is nonempty; see n0r 3535. (Contributed by David A. Wheeler, 20-Jul-2026.)
Hypothesis
Ref Expression
ralsmd.1  |-  ( ph  ->  A.E. x  e.  A ( ps  ->  ch ) )
Assertion
Ref Expression
ralsmd  |-  ( ph  ->  E. x  x  e.  A )
Distinct variable group:    x, A
Allowed substitution hints:    ph( x)    ps( x)    ch( x)

Proof of Theorem ralsmd
StepHypRef Expression
1 ralsmd.1 . . 3  |-  ( ph  ->  A.E. x  e.  A ( ps  ->  ch ) )
21rals2d 17136 . 2  |-  ( ph  ->  E. x  e.  A  ps )
3 rexm 3627 . 2  |-  ( E. x  e.  A  ps  ->  E. x  x  e.  A )
42, 3syl 14 1  |-  ( ph  ->  E. x  x  e.  A )
Colors of variables:    wff set class
This proof depends on syntax axioms:    -> wi 4   E.wex 1545    e. wcel 2209   E.wrex 2529   A.E.wrals 17127
This proof depends on 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-ial 1587
This proof depends on definitions:  df-bi 117  df-rex 2534  df-rals 17129
This theorem is used by: (None)
  Copyright terms: Public domain W3C validator