| Step | Hyp | Ref | Expression | 
						
							| 1 |  | zlmodzxz.z |  |-  Z = ( ZZring freeLMod { 0 , 1 } ) | 
						
							| 2 |  | zlmodzxzsub.m |  |-  .- = ( -g ` Z ) | 
						
							| 3 | 1 | zlmodzxzlmod |  |-  ( Z e. LMod /\ ZZring = ( Scalar ` Z ) ) | 
						
							| 4 | 3 | simpli |  |-  Z e. LMod | 
						
							| 5 | 4 | a1i |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> Z e. LMod ) | 
						
							| 6 | 1 | zlmodzxzel |  |-  ( ( A e. ZZ /\ C e. ZZ ) -> { <. 0 , A >. , <. 1 , C >. } e. ( Base ` Z ) ) | 
						
							| 7 | 6 | ad2ant2r |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> { <. 0 , A >. , <. 1 , C >. } e. ( Base ` Z ) ) | 
						
							| 8 | 1 | zlmodzxzel |  |-  ( ( B e. ZZ /\ D e. ZZ ) -> { <. 0 , B >. , <. 1 , D >. } e. ( Base ` Z ) ) | 
						
							| 9 | 8 | ad2ant2l |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> { <. 0 , B >. , <. 1 , D >. } e. ( Base ` Z ) ) | 
						
							| 10 |  | eqid |  |-  ( Base ` Z ) = ( Base ` Z ) | 
						
							| 11 |  | eqid |  |-  ( +g ` Z ) = ( +g ` Z ) | 
						
							| 12 | 3 | simpri |  |-  ZZring = ( Scalar ` Z ) | 
						
							| 13 |  | eqid |  |-  ( .s ` Z ) = ( .s ` Z ) | 
						
							| 14 |  | eqid |  |-  ( invg ` ZZring ) = ( invg ` ZZring ) | 
						
							| 15 |  | zring1 |  |-  1 = ( 1r ` ZZring ) | 
						
							| 16 | 10 11 2 12 13 14 15 | lmodvsubval2 |  |-  ( ( Z e. LMod /\ { <. 0 , A >. , <. 1 , C >. } e. ( Base ` Z ) /\ { <. 0 , B >. , <. 1 , D >. } e. ( Base ` Z ) ) -> ( { <. 0 , A >. , <. 1 , C >. } .- { <. 0 , B >. , <. 1 , D >. } ) = ( { <. 0 , A >. , <. 1 , C >. } ( +g ` Z ) ( ( ( invg ` ZZring ) ` 1 ) ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) ) ) | 
						
							| 17 | 5 7 9 16 | syl3anc |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> ( { <. 0 , A >. , <. 1 , C >. } .- { <. 0 , B >. , <. 1 , D >. } ) = ( { <. 0 , A >. , <. 1 , C >. } ( +g ` Z ) ( ( ( invg ` ZZring ) ` 1 ) ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) ) ) | 
						
							| 18 |  | 1z |  |-  1 e. ZZ | 
						
							| 19 |  | zringinvg |  |-  ( 1 e. ZZ -> -u 1 = ( ( invg ` ZZring ) ` 1 ) ) | 
						
							| 20 | 18 19 | mp1i |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> -u 1 = ( ( invg ` ZZring ) ` 1 ) ) | 
						
							| 21 | 20 | eqcomd |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> ( ( invg ` ZZring ) ` 1 ) = -u 1 ) | 
						
							| 22 | 21 | oveq1d |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> ( ( ( invg ` ZZring ) ` 1 ) ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) = ( -u 1 ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) ) | 
						
							| 23 | 22 | oveq2d |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> ( { <. 0 , A >. , <. 1 , C >. } ( +g ` Z ) ( ( ( invg ` ZZring ) ` 1 ) ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) ) = ( { <. 0 , A >. , <. 1 , C >. } ( +g ` Z ) ( -u 1 ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) ) ) | 
						
							| 24 | 17 23 | eqtrd |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( C e. ZZ /\ D e. ZZ ) ) -> ( { <. 0 , A >. , <. 1 , C >. } .- { <. 0 , B >. , <. 1 , D >. } ) = ( { <. 0 , A >. , <. 1 , C >. } ( +g ` Z ) ( -u 1 ( .s ` Z ) { <. 0 , B >. , <. 1 , D >. } ) ) ) |