| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mnringvald.1 |  |-  F = ( R MndRing M ) | 
						
							| 2 |  | mnringvald.2 |  |-  .x. = ( .r ` R ) | 
						
							| 3 |  | mnringvald.3 |  |-  .0. = ( 0g ` R ) | 
						
							| 4 |  | mnringvald.4 |  |-  A = ( Base ` M ) | 
						
							| 5 |  | mnringvald.5 |  |-  .+ = ( +g ` M ) | 
						
							| 6 |  | mnringvald.6 |  |-  V = ( R freeLMod A ) | 
						
							| 7 |  | mnringvald.7 |  |-  B = ( Base ` V ) | 
						
							| 8 |  | mnringvald.8 |  |-  ( ph -> R e. U ) | 
						
							| 9 |  | mnringvald.9 |  |-  ( ph -> M e. W ) | 
						
							| 10 | 8 | elexd |  |-  ( ph -> R e. _V ) | 
						
							| 11 | 9 | elexd |  |-  ( ph -> M e. _V ) | 
						
							| 12 |  | nfv |  |-  F/ v ( r = R /\ m = M ) | 
						
							| 13 |  | nfcvd |  |-  ( ( r = R /\ m = M ) -> F/_ v ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) ) | 
						
							| 14 |  | ovexd |  |-  ( ( r = R /\ m = M ) -> ( r freeLMod ( Base ` m ) ) e. _V ) | 
						
							| 15 |  | simpr |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> v = ( r freeLMod ( Base ` m ) ) ) | 
						
							| 16 |  | simpll |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> r = R ) | 
						
							| 17 |  | fveq2 |  |-  ( m = M -> ( Base ` m ) = ( Base ` M ) ) | 
						
							| 18 | 17 4 | eqtr4di |  |-  ( m = M -> ( Base ` m ) = A ) | 
						
							| 19 | 18 | ad2antlr |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( Base ` m ) = A ) | 
						
							| 20 | 16 19 | oveq12d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( r freeLMod ( Base ` m ) ) = ( R freeLMod A ) ) | 
						
							| 21 | 15 20 | eqtrd |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> v = ( R freeLMod A ) ) | 
						
							| 22 | 21 6 | eqtr4di |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> v = V ) | 
						
							| 23 | 22 | fveq2d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( Base ` v ) = ( Base ` V ) ) | 
						
							| 24 | 23 7 | eqtr4di |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( Base ` v ) = B ) | 
						
							| 25 |  | fveq2 |  |-  ( m = M -> ( +g ` m ) = ( +g ` M ) ) | 
						
							| 26 | 25 5 | eqtr4di |  |-  ( m = M -> ( +g ` m ) = .+ ) | 
						
							| 27 | 26 | oveqd |  |-  ( m = M -> ( a ( +g ` m ) b ) = ( a .+ b ) ) | 
						
							| 28 | 27 | ad2antlr |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( a ( +g ` m ) b ) = ( a .+ b ) ) | 
						
							| 29 | 28 | eqeq2d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( i = ( a ( +g ` m ) b ) <-> i = ( a .+ b ) ) ) | 
						
							| 30 |  | fveq2 |  |-  ( r = R -> ( .r ` r ) = ( .r ` R ) ) | 
						
							| 31 | 30 2 | eqtr4di |  |-  ( r = R -> ( .r ` r ) = .x. ) | 
						
							| 32 | 31 | oveqd |  |-  ( r = R -> ( ( x ` a ) ( .r ` r ) ( y ` b ) ) = ( ( x ` a ) .x. ( y ` b ) ) ) | 
						
							| 33 | 32 | ad2antrr |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( ( x ` a ) ( .r ` r ) ( y ` b ) ) = ( ( x ` a ) .x. ( y ` b ) ) ) | 
						
							| 34 |  | fveq2 |  |-  ( r = R -> ( 0g ` r ) = ( 0g ` R ) ) | 
						
							| 35 | 34 3 | eqtr4di |  |-  ( r = R -> ( 0g ` r ) = .0. ) | 
						
							| 36 | 35 | ad2antrr |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( 0g ` r ) = .0. ) | 
						
							| 37 | 29 33 36 | ifbieq12d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) = if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) | 
						
							| 38 | 19 37 | mpteq12dv |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) = ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) | 
						
							| 39 | 19 19 38 | mpoeq123dv |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) = ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) | 
						
							| 40 | 22 39 | oveq12d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( v gsum ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) ) = ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) | 
						
							| 41 | 24 24 40 | mpoeq123dv |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( x e. ( Base ` v ) , y e. ( Base ` v ) |-> ( v gsum ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) ) ) = ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) ) | 
						
							| 42 | 41 | opeq2d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> <. ( .r ` ndx ) , ( x e. ( Base ` v ) , y e. ( Base ` v ) |-> ( v gsum ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) ) ) >. = <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) | 
						
							| 43 | 22 42 | oveq12d |  |-  ( ( ( r = R /\ m = M ) /\ v = ( r freeLMod ( Base ` m ) ) ) -> ( v sSet <. ( .r ` ndx ) , ( x e. ( Base ` v ) , y e. ( Base ` v ) |-> ( v gsum ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) ) ) >. ) = ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) ) | 
						
							| 44 | 12 13 14 43 | csbiedf |  |-  ( ( r = R /\ m = M ) -> [_ ( r freeLMod ( Base ` m ) ) / v ]_ ( v sSet <. ( .r ` ndx ) , ( x e. ( Base ` v ) , y e. ( Base ` v ) |-> ( v gsum ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) ) ) >. ) = ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) ) | 
						
							| 45 |  | df-mnring |  |-  MndRing = ( r e. _V , m e. _V |-> [_ ( r freeLMod ( Base ` m ) ) / v ]_ ( v sSet <. ( .r ` ndx ) , ( x e. ( Base ` v ) , y e. ( Base ` v ) |-> ( v gsum ( a e. ( Base ` m ) , b e. ( Base ` m ) |-> ( i e. ( Base ` m ) |-> if ( i = ( a ( +g ` m ) b ) , ( ( x ` a ) ( .r ` r ) ( y ` b ) ) , ( 0g ` r ) ) ) ) ) ) >. ) ) | 
						
							| 46 |  | ovex |  |-  ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) e. _V | 
						
							| 47 | 44 45 46 | ovmpoa |  |-  ( ( R e. _V /\ M e. _V ) -> ( R MndRing M ) = ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) ) | 
						
							| 48 | 10 11 47 | syl2anc |  |-  ( ph -> ( R MndRing M ) = ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) ) | 
						
							| 49 | 1 48 | eqtrid |  |-  ( ph -> F = ( V sSet <. ( .r ` ndx ) , ( x e. B , y e. B |-> ( V gsum ( a e. A , b e. A |-> ( i e. A |-> if ( i = ( a .+ b ) , ( ( x ` a ) .x. ( y ` b ) ) , .0. ) ) ) ) ) >. ) ) |