Theorem po3nr 4401

Description: A partial order relation has no 3-cycle loops. (Contributed by NM, 27-Mar-1997.)

Assertion

Ref	Expression
po3nr	|- ( ( R Po A /\ ( B e. A /\ C e. A /\ D e. A ) ) -> -. ( B R C /\ C R D /\ D R B ) )

Proof of Theorem po3nr

Step	Hyp	Ref	Expression
1		po2nr 4400	. . 3 |- ( ( R Po A /\ ( B e. A /\ D e. A ) ) -> -. ( B R D /\ D R B ) )
2	1	3adantr2 1181	. 2 |- ( ( R Po A /\ ( B e. A /\ C e. A /\ D e. A ) ) -> -. ( B R D /\ D R B ) )
3		df-3an 1004	. . 3 |- ( ( B R C /\ C R D /\ D R B ) <-> ( ( B R C /\ C R D ) /\ D R B ) )
4		potr 4399	. . . 4 |- ( ( R Po A /\ ( B e. A /\ C e. A /\ D e. A ) ) -> ( ( B R C /\ C R D ) -> B R D ) )
5	4	anim1d 336	. . 3 |- ( ( R Po A /\ ( B e. A /\ C e. A /\ D e. A ) ) -> ( ( ( B R C /\ C R D ) /\ D R B ) -> ( B R D /\ D R B ) ) )
6	3, 5	biimtrid 152	. 2 |- ( ( R Po A /\ ( B e. A /\ C e. A /\ D e. A ) ) -> ( ( B R C /\ C R D /\ D R B ) -> ( B R D /\ D R B ) ) )
7	2, 6	mtod 667	1 |- ( ( R Po A /\ ( B e. A /\ C e. A /\ D e. A ) ) -> -. ( B R C /\ C R D /\ D R B ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   /\ w3a 1002   e. wcel 2200   class class class wbr 4083   Po wpo 4385

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-in1 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-ext 2211

This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-v 2801  df-un 3201  df-sn 3672  df-pr 3673  df-op 3675  df-br 4084  df-po 4387

This theorem is referenced by:  so3nr  4413