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

Theorem barbari 2116
Description: "Barbari", one of the syllogisms of Aristotelian logic. All  ph is  ps, all  ch is  ph, and some  ch exist, therefore some  ch is  ps. (In Aristotelian notation, AAI-1: MaP and SaM therefore SiP.) For example, given "All men are mortal", "All Greeks are men", and "Greeks exist", therefore "Some Greeks are mortal". Note the existence hypothesis (to prove the "some" in the conclusion). Example from https://en.wikipedia.org/wiki/Syllogism. (Contributed by David A. Wheeler, 27-Aug-2016.) (Revised by David A. Wheeler, 30-Aug-2016.)
Hypotheses
Ref Expression
barbari.maj  |-  A. x
( ph  ->  ps )
barbari.min  |-  A. x
( ch  ->  ph )
barbari.e  |-  E. x ch
Assertion
Ref Expression
barbari  |-  E. x
( ch  /\  ps )

Proof of Theorem barbari
StepHypRef Expression
1 barbari.e . 2  |-  E. x ch
2 barbari.maj . . . . 5  |-  A. x
( ph  ->  ps )
3 barbari.min . . . . 5  |-  A. x
( ch  ->  ph )
42, 3barbara 2112 . . . 4  |-  A. x
( ch  ->  ps )
54spi 1524 . . 3  |-  ( ch 
->  ps )
65ancli 321 . 2  |-  ( ch 
->  ( ch  /\  ps ) )
71, 6eximii 1590 1  |-  E. x
( ch  /\  ps )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103   A.wal 1341   E.wex 1480
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
This theorem is referenced by:  celaront  2117
  Copyright terms: Public domain W3C validator