Users' Mathboxes Mathbox for Richard Penner < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  frege65a Structured version   Visualization version   Unicode version

Theorem frege65a 38177
Description: A kind of Aristotelian inference. This judgement replaces the mode of inference barbara 2563 when the minor premise has a general context. Proposition 65 of [Frege1879] p. 53. (Contributed by RP, 17-Apr-2020.) (Proof modification is discouraged.)
Assertion
Ref Expression
frege65a  |-  ( ( ( ps  ->  ch )  /\  ( ta  ->  et ) )  ->  (
( ( ch  ->  th )  /\  ( et 
->  ze ) )  -> 
(if- ( ph ,  ps ,  ta )  -> if- ( ph ,  th ,  ze ) ) ) )

Proof of Theorem frege65a
StepHypRef Expression
1 ifpimim 37854 . . 3  |-  (if- (
ph ,  ( ps 
->  ch ) ,  ( ta  ->  et )
)  ->  (if- ( ph ,  ps ,  ta )  -> if- ( ph ,  ch ,  et )
) )
2 frege64a 38176 . . 3  |-  ( (if- ( ph ,  ps ,  ta )  -> if- ( ph ,  ch ,  et ) )  ->  ( (
( ch  ->  th )  /\  ( et  ->  ze )
)  ->  (if- ( ph ,  ps ,  ta )  -> if- ( ph ,  th ,  ze )
) ) )
31, 2syl 17 . 2  |-  (if- (
ph ,  ( ps 
->  ch ) ,  ( ta  ->  et )
)  ->  ( (
( ch  ->  th )  /\  ( et  ->  ze )
)  ->  (if- ( ph ,  ps ,  ta )  -> if- ( ph ,  th ,  ze )
) ) )
4 frege61a 38173 . 2  |-  ( (if- ( ph ,  ( ps  ->  ch ) ,  ( ta  ->  et ) )  ->  (
( ( ch  ->  th )  /\  ( et 
->  ze ) )  -> 
(if- ( ph ,  ps ,  ta )  -> if- ( ph ,  th ,  ze ) ) ) )  ->  ( (
( ps  ->  ch )  /\  ( ta  ->  et ) )  ->  (
( ( ch  ->  th )  /\  ( et 
->  ze ) )  -> 
(if- ( ph ,  ps ,  ta )  -> if- ( ph ,  th ,  ze ) ) ) ) )
53, 4ax-mp 5 1  |-  ( ( ( ps  ->  ch )  /\  ( ta  ->  et ) )  ->  (
( ( ch  ->  th )  /\  ( et 
->  ze ) )  -> 
(if- ( ph ,  ps ,  ta )  -> if- ( ph ,  th ,  ze ) ) ) )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    /\ wa 384  if-wif 1012
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-frege1 38084  ax-frege2 38085  ax-frege8 38103  ax-frege58a 38169
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-ifp 1013
This theorem is referenced by:  frege66a  38178
  Copyright terms: Public domain W3C validator