Metamath Proof Explorer


Theorem orngsqr

Description: In an ordered ring, all squares are positive. (Contributed by Thierry Arnoux, 20-Jan-2018)

Ref Expression
Hypotheses orngmul.0
|- B = ( Base ` R )
orngmul.1
|- .<_ = ( le ` R )
orngmul.2
|- .0. = ( 0g ` R )
orngmul.3
|- .x. = ( .r ` R )
Assertion orngsqr
|- ( ( R e. oRing /\ X e. B ) -> .0. .<_ ( X .x. X ) )

Proof

Step Hyp Ref Expression
1 orngmul.0
 |-  B = ( Base ` R )
2 orngmul.1
 |-  .<_ = ( le ` R )
3 orngmul.2
 |-  .0. = ( 0g ` R )
4 orngmul.3
 |-  .x. = ( .r ` R )
5 simpll
 |-  ( ( ( R e. oRing /\ X e. B ) /\ .0. .<_ X ) -> R e. oRing )
6 simplr
 |-  ( ( ( R e. oRing /\ X e. B ) /\ .0. .<_ X ) -> X e. B )
7 simpr
 |-  ( ( ( R e. oRing /\ X e. B ) /\ .0. .<_ X ) -> .0. .<_ X )
8 1 2 3 4 orngmul
 |-  ( ( R e. oRing /\ ( X e. B /\ .0. .<_ X ) /\ ( X e. B /\ .0. .<_ X ) ) -> .0. .<_ ( X .x. X ) )
9 5 6 7 6 7 8 syl122anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ .0. .<_ X ) -> .0. .<_ ( X .x. X ) )
10 simpll
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> R e. oRing )
11 orngring
 |-  ( R e. oRing -> R e. Ring )
12 11 ad2antrr
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> R e. Ring )
13 ringgrp
 |-  ( R e. Ring -> R e. Grp )
14 12 13 syl
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> R e. Grp )
15 simplr
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> X e. B )
16 eqid
 |-  ( invg ` R ) = ( invg ` R )
17 1 16 grpinvcl
 |-  ( ( R e. Grp /\ X e. B ) -> ( ( invg ` R ) ` X ) e. B )
18 14 15 17 syl2anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( ( invg ` R ) ` X ) e. B )
19 orngogrp
 |-  ( R e. oRing -> R e. oGrp )
20 isogrp
 |-  ( R e. oGrp <-> ( R e. Grp /\ R e. oMnd ) )
21 20 simprbi
 |-  ( R e. oGrp -> R e. oMnd )
22 19 21 syl
 |-  ( R e. oRing -> R e. oMnd )
23 10 22 syl
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> R e. oMnd )
24 1 3 grpidcl
 |-  ( R e. Grp -> .0. e. B )
25 14 24 syl
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> .0. e. B )
26 simpl
 |-  ( ( R e. oRing /\ X e. B ) -> R e. oRing )
27 11 13 24 3syl
 |-  ( R e. oRing -> .0. e. B )
28 26 27 syl
 |-  ( ( R e. oRing /\ X e. B ) -> .0. e. B )
29 simpr
 |-  ( ( R e. oRing /\ X e. B ) -> X e. B )
30 26 28 29 3jca
 |-  ( ( R e. oRing /\ X e. B ) -> ( R e. oRing /\ .0. e. B /\ X e. B ) )
31 eqid
 |-  ( lt ` R ) = ( lt ` R )
32 2 31 pltle
 |-  ( ( R e. oRing /\ .0. e. B /\ X e. B ) -> ( .0. ( lt ` R ) X -> .0. .<_ X ) )
33 32 con3dimp
 |-  ( ( ( R e. oRing /\ .0. e. B /\ X e. B ) /\ -. .0. .<_ X ) -> -. .0. ( lt ` R ) X )
34 30 33 sylan
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> -. .0. ( lt ` R ) X )
35 omndtos
 |-  ( R e. oMnd -> R e. Toset )
36 22 35 syl
 |-  ( R e. oRing -> R e. Toset )
37 1 2 31 tosso
 |-  ( R e. Toset -> ( R e. Toset <-> ( ( lt ` R ) Or B /\ ( _I |` B ) C_ .<_ ) ) )
38 37 ibi
 |-  ( R e. Toset -> ( ( lt ` R ) Or B /\ ( _I |` B ) C_ .<_ ) )
39 38 simpld
 |-  ( R e. Toset -> ( lt ` R ) Or B )
40 10 36 39 3syl
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( lt ` R ) Or B )
41 solin
 |-  ( ( ( lt ` R ) Or B /\ ( .0. e. B /\ X e. B ) ) -> ( .0. ( lt ` R ) X \/ .0. = X \/ X ( lt ` R ) .0. ) )
42 40 25 15 41 syl12anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( .0. ( lt ` R ) X \/ .0. = X \/ X ( lt ` R ) .0. ) )
43 3orass
 |-  ( ( .0. ( lt ` R ) X \/ .0. = X \/ X ( lt ` R ) .0. ) <-> ( .0. ( lt ` R ) X \/ ( .0. = X \/ X ( lt ` R ) .0. ) ) )
44 42 43 sylib
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( .0. ( lt ` R ) X \/ ( .0. = X \/ X ( lt ` R ) .0. ) ) )
45 orel1
 |-  ( -. .0. ( lt ` R ) X -> ( ( .0. ( lt ` R ) X \/ ( .0. = X \/ X ( lt ` R ) .0. ) ) -> ( .0. = X \/ X ( lt ` R ) .0. ) ) )
46 34 44 45 sylc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( .0. = X \/ X ( lt ` R ) .0. ) )
47 orcom
 |-  ( ( .0. = X \/ X ( lt ` R ) .0. ) <-> ( X ( lt ` R ) .0. \/ .0. = X ) )
48 eqcom
 |-  ( .0. = X <-> X = .0. )
49 48 orbi2i
 |-  ( ( X ( lt ` R ) .0. \/ .0. = X ) <-> ( X ( lt ` R ) .0. \/ X = .0. ) )
50 47 49 bitri
 |-  ( ( .0. = X \/ X ( lt ` R ) .0. ) <-> ( X ( lt ` R ) .0. \/ X = .0. ) )
51 46 50 sylib
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( X ( lt ` R ) .0. \/ X = .0. ) )
52 tospos
 |-  ( R e. Toset -> R e. Poset )
53 10 36 52 3syl
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> R e. Poset )
54 1 2 31 pleval2
 |-  ( ( R e. Poset /\ X e. B /\ .0. e. B ) -> ( X .<_ .0. <-> ( X ( lt ` R ) .0. \/ X = .0. ) ) )
55 53 15 25 54 syl3anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( X .<_ .0. <-> ( X ( lt ` R ) .0. \/ X = .0. ) ) )
56 51 55 mpbird
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> X .<_ .0. )
57 eqid
 |-  ( +g ` R ) = ( +g ` R )
58 1 2 57 omndadd
 |-  ( ( R e. oMnd /\ ( X e. B /\ .0. e. B /\ ( ( invg ` R ) ` X ) e. B ) /\ X .<_ .0. ) -> ( X ( +g ` R ) ( ( invg ` R ) ` X ) ) .<_ ( .0. ( +g ` R ) ( ( invg ` R ) ` X ) ) )
59 23 15 25 18 56 58 syl131anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( X ( +g ` R ) ( ( invg ` R ) ` X ) ) .<_ ( .0. ( +g ` R ) ( ( invg ` R ) ` X ) ) )
60 1 57 3 16 grprinv
 |-  ( ( R e. Grp /\ X e. B ) -> ( X ( +g ` R ) ( ( invg ` R ) ` X ) ) = .0. )
61 14 15 60 syl2anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( X ( +g ` R ) ( ( invg ` R ) ` X ) ) = .0. )
62 1 57 3 grplid
 |-  ( ( R e. Grp /\ ( ( invg ` R ) ` X ) e. B ) -> ( .0. ( +g ` R ) ( ( invg ` R ) ` X ) ) = ( ( invg ` R ) ` X ) )
63 14 18 62 syl2anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( .0. ( +g ` R ) ( ( invg ` R ) ` X ) ) = ( ( invg ` R ) ` X ) )
64 59 61 63 3brtr3d
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> .0. .<_ ( ( invg ` R ) ` X ) )
65 1 2 3 4 orngmul
 |-  ( ( R e. oRing /\ ( ( ( invg ` R ) ` X ) e. B /\ .0. .<_ ( ( invg ` R ) ` X ) ) /\ ( ( ( invg ` R ) ` X ) e. B /\ .0. .<_ ( ( invg ` R ) ` X ) ) ) -> .0. .<_ ( ( ( invg ` R ) ` X ) .x. ( ( invg ` R ) ` X ) ) )
66 10 18 64 18 64 65 syl122anc
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> .0. .<_ ( ( ( invg ` R ) ` X ) .x. ( ( invg ` R ) ` X ) ) )
67 1 4 16 12 15 15 ringm2neg
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> ( ( ( invg ` R ) ` X ) .x. ( ( invg ` R ) ` X ) ) = ( X .x. X ) )
68 66 67 breqtrd
 |-  ( ( ( R e. oRing /\ X e. B ) /\ -. .0. .<_ X ) -> .0. .<_ ( X .x. X ) )
69 9 68 pm2.61dan
 |-  ( ( R e. oRing /\ X e. B ) -> .0. .<_ ( X .x. X ) )