ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  rexrab Unicode version

Theorem rexrab 2704
Description: Existential quantification over a class abstraction. (Contributed by Jeff Madsen, 17-Jun-2011.) (Revised by Mario Carneiro, 3-Sep-2015.)
Hypothesis
Ref Expression
ralab.1  |-  ( y  =  x  ->  ( ph 
<->  ps ) )
Assertion
Ref Expression
rexrab  |-  ( E. x  e.  { y  e.  A  |  ph } ch  <->  E. x  e.  A  ( ps  /\  ch )
)
Distinct variable groups:    x, y    y, A    ps, y
Allowed substitution hints:    ph( x, y)    ps( x)    ch( x, y)    A( x)

Proof of Theorem rexrab
StepHypRef Expression
1 ralab.1 . . . . 5  |-  ( y  =  x  ->  ( ph 
<->  ps ) )
21elrab 2698 . . . 4  |-  ( x  e.  { y  e.  A  |  ph }  <->  ( x  e.  A  /\  ps ) )
32anbi1i 431 . . 3  |-  ( ( x  e.  { y  e.  A  |  ph }  /\  ch )  <->  ( (
x  e.  A  /\  ps )  /\  ch )
)
4 anass 381 . . 3  |-  ( ( ( x  e.  A  /\  ps )  /\  ch ) 
<->  ( x  e.  A  /\  ( ps  /\  ch ) ) )
53, 4bitri 173 . 2  |-  ( ( x  e.  { y  e.  A  |  ph }  /\  ch )  <->  ( x  e.  A  /\  ( ps  /\  ch ) ) )
65rexbii2 2335 1  |-  ( E. x  e.  { y  e.  A  |  ph } ch  <->  E. x  e.  A  ( ps  /\  ch )
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 97    <-> wb 98    e. wcel 1393   E.wrex 2307   {crab 2310
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022
This theorem depends on definitions:  df-bi 110  df-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-rex 2312  df-rab 2315  df-v 2559
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator