Theorem ltleletr 7717

Description: Transitive law, weaker form of ( A < B /\ B <_ C ) -> A < C. (Contributed by AV, 14-Oct-2018.)

Assertion

Ref	Expression
ltleletr	|- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( ( A < B /\ B <_ C ) -> A <_ C ) )

Proof of Theorem ltleletr

Step	Hyp	Ref	Expression
1		lttr 7709	. . . . . 6 |- ( ( C e. RR /\ A e. RR /\ B e. RR ) -> ( ( C < A /\ A < B ) -> C < B ) )
2	1	3coml 1156	. . . . 5 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( ( C < A /\ A < B ) -> C < B ) )
3	2	expcomd 1385	. . . 4 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( A < B -> ( C < A -> C < B ) ) )
4		con3 611	. . . 4 |- ( ( C < A -> C < B ) -> ( -. C < B -> -. C < A ) )
5	3, 4	syl6 33	. . 3 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( A < B -> ( -. C < B -> -. C < A ) ) )
6		lenlt 7711	. . . . 5 |- ( ( B e. RR /\ C e. RR ) -> ( B <_ C <-> -. C < B ) )
7	6	3adant1 967	. . . 4 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( B <_ C <-> -. C < B ) )
8		lenlt 7711	. . . . 5 |- ( ( A e. RR /\ C e. RR ) -> ( A <_ C <-> -. C < A ) )
9	8	3adant2 968	. . . 4 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( A <_ C <-> -. C < A ) )
10	7, 9	imbi12d 233	. . 3 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( ( B <_ C -> A <_ C ) <-> ( -. C < B -> -. C < A ) ) )
11	5, 10	sylibrd 168	. 2 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( A < B -> ( B <_ C -> A <_ C ) ) )
12	11	impd 252	1 |- ( ( A e. RR /\ B e. RR /\ C e. RR ) -> ( ( A < B /\ B <_ C ) -> A <_ C ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 103   <-> wb 104   /\ w3a 930   e. wcel 1448   class class class wbr 3875   RRcr 7499   < clt 7672   <_ cle 7673

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 584  ax-in2 585  ax-io 671  ax-5 1391  ax-7 1392  ax-gen 1393  ax-ie1 1437  ax-ie2 1438  ax-8 1450  ax-10 1451  ax-11 1452  ax-i12 1453  ax-bndl 1454  ax-4 1455  ax-13 1459  ax-14 1460  ax-17 1474  ax-i9 1478  ax-ial 1482  ax-i5r 1483  ax-ext 2082  ax-sep 3986  ax-pow 4038  ax-pr 4069  ax-un 4293  ax-setind 4390  ax-cnex 7586  ax-resscn 7587  ax-pre-lttrn 7609

This theorem depends on definitions:  df-bi 116  df-3an 932  df-tru 1302  df-fal 1305  df-nf 1405  df-sb 1704  df-eu 1963  df-mo 1964  df-clab 2087  df-cleq 2093  df-clel 2096  df-nfc 2229  df-ne 2268  df-nel 2363  df-ral 2380  df-rex 2381  df-rab 2384  df-v 2643  df-dif 3023  df-un 3025  df-in 3027  df-ss 3034  df-pw 3459  df-sn 3480  df-pr 3481  df-op 3483  df-uni 3684  df-br 3876  df-opab 3930  df-xp 4483  df-cnv 4485  df-pnf 7674  df-mnf 7675  df-xr 7676  df-ltxr 7677  df-le 7678

This theorem is referenced by:  nn0ge2m1nn  8889  lbzbi  9258  iseqf1olemqk  10108