| Step | Hyp | Ref | Expression | 
						
							| 1 |  | refld |  |-  RRfld e. Field | 
						
							| 2 |  | isfld |  |-  ( RRfld e. Field <-> ( RRfld e. DivRing /\ RRfld e. CRing ) ) | 
						
							| 3 | 2 | simplbi |  |-  ( RRfld e. Field -> RRfld e. DivRing ) | 
						
							| 4 |  | drngring |  |-  ( RRfld e. DivRing -> RRfld e. Ring ) | 
						
							| 5 | 1 3 4 | mp2b |  |-  RRfld e. Ring | 
						
							| 6 |  | ringgrp |  |-  ( RRfld e. Ring -> RRfld e. Grp ) | 
						
							| 7 | 5 6 | ax-mp |  |-  RRfld e. Grp | 
						
							| 8 |  | grpmnd |  |-  ( RRfld e. Grp -> RRfld e. Mnd ) | 
						
							| 9 | 7 8 | ax-mp |  |-  RRfld e. Mnd | 
						
							| 10 |  | retos |  |-  RRfld e. Toset | 
						
							| 11 |  | simpl |  |-  ( ( a e. RR /\ ( b e. RR /\ c e. RR /\ a <_ b ) ) -> a e. RR ) | 
						
							| 12 |  | simpr1 |  |-  ( ( a e. RR /\ ( b e. RR /\ c e. RR /\ a <_ b ) ) -> b e. RR ) | 
						
							| 13 |  | simpr2 |  |-  ( ( a e. RR /\ ( b e. RR /\ c e. RR /\ a <_ b ) ) -> c e. RR ) | 
						
							| 14 |  | simpr3 |  |-  ( ( a e. RR /\ ( b e. RR /\ c e. RR /\ a <_ b ) ) -> a <_ b ) | 
						
							| 15 | 11 12 13 14 | leadd1dd |  |-  ( ( a e. RR /\ ( b e. RR /\ c e. RR /\ a <_ b ) ) -> ( a + c ) <_ ( b + c ) ) | 
						
							| 16 | 15 | 3anassrs |  |-  ( ( ( ( a e. RR /\ b e. RR ) /\ c e. RR ) /\ a <_ b ) -> ( a + c ) <_ ( b + c ) ) | 
						
							| 17 | 16 | ex |  |-  ( ( ( a e. RR /\ b e. RR ) /\ c e. RR ) -> ( a <_ b -> ( a + c ) <_ ( b + c ) ) ) | 
						
							| 18 | 17 | 3impa |  |-  ( ( a e. RR /\ b e. RR /\ c e. RR ) -> ( a <_ b -> ( a + c ) <_ ( b + c ) ) ) | 
						
							| 19 | 18 | rgen3 |  |-  A. a e. RR A. b e. RR A. c e. RR ( a <_ b -> ( a + c ) <_ ( b + c ) ) | 
						
							| 20 |  | rebase |  |-  RR = ( Base ` RRfld ) | 
						
							| 21 |  | replusg |  |-  + = ( +g ` RRfld ) | 
						
							| 22 |  | rele2 |  |-  <_ = ( le ` RRfld ) | 
						
							| 23 | 20 21 22 | isomnd |  |-  ( RRfld e. oMnd <-> ( RRfld e. Mnd /\ RRfld e. Toset /\ A. a e. RR A. b e. RR A. c e. RR ( a <_ b -> ( a + c ) <_ ( b + c ) ) ) ) | 
						
							| 24 | 9 10 19 23 | mpbir3an |  |-  RRfld e. oMnd | 
						
							| 25 |  | isogrp |  |-  ( RRfld e. oGrp <-> ( RRfld e. Grp /\ RRfld e. oMnd ) ) | 
						
							| 26 | 7 24 25 | mpbir2an |  |-  RRfld e. oGrp | 
						
							| 27 |  | mulge0 |  |-  ( ( ( a e. RR /\ 0 <_ a ) /\ ( b e. RR /\ 0 <_ b ) ) -> 0 <_ ( a x. b ) ) | 
						
							| 28 | 27 | an4s |  |-  ( ( ( a e. RR /\ b e. RR ) /\ ( 0 <_ a /\ 0 <_ b ) ) -> 0 <_ ( a x. b ) ) | 
						
							| 29 | 28 | ex |  |-  ( ( a e. RR /\ b e. RR ) -> ( ( 0 <_ a /\ 0 <_ b ) -> 0 <_ ( a x. b ) ) ) | 
						
							| 30 | 29 | rgen2 |  |-  A. a e. RR A. b e. RR ( ( 0 <_ a /\ 0 <_ b ) -> 0 <_ ( a x. b ) ) | 
						
							| 31 |  | re0g |  |-  0 = ( 0g ` RRfld ) | 
						
							| 32 |  | remulr |  |-  x. = ( .r ` RRfld ) | 
						
							| 33 | 20 31 32 22 | isorng |  |-  ( RRfld e. oRing <-> ( RRfld e. Ring /\ RRfld e. oGrp /\ A. a e. RR A. b e. RR ( ( 0 <_ a /\ 0 <_ b ) -> 0 <_ ( a x. b ) ) ) ) | 
						
							| 34 | 5 26 30 33 | mpbir3an |  |-  RRfld e. oRing | 
						
							| 35 |  | isofld |  |-  ( RRfld e. oField <-> ( RRfld e. Field /\ RRfld e. oRing ) ) | 
						
							| 36 | 1 34 35 | mpbir2an |  |-  RRfld e. oField |