| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prdsmgp.y |  |-  Y = ( S Xs_ R ) | 
						
							| 2 |  | prdsmgp.m |  |-  M = ( mulGrp ` Y ) | 
						
							| 3 |  | prdsmgp.z |  |-  Z = ( S Xs_ ( mulGrp o. R ) ) | 
						
							| 4 |  | prdsmgp.i |  |-  ( ph -> I e. V ) | 
						
							| 5 |  | prdsmgp.s |  |-  ( ph -> S e. W ) | 
						
							| 6 |  | prdsmgp.r |  |-  ( ph -> R Fn I ) | 
						
							| 7 |  | eqid |  |-  ( mulGrp ` ( R ` x ) ) = ( mulGrp ` ( R ` x ) ) | 
						
							| 8 |  | eqid |  |-  ( Base ` ( R ` x ) ) = ( Base ` ( R ` x ) ) | 
						
							| 9 | 7 8 | mgpbas |  |-  ( Base ` ( R ` x ) ) = ( Base ` ( mulGrp ` ( R ` x ) ) ) | 
						
							| 10 |  | fvco2 |  |-  ( ( R Fn I /\ x e. I ) -> ( ( mulGrp o. R ) ` x ) = ( mulGrp ` ( R ` x ) ) ) | 
						
							| 11 | 6 10 | sylan |  |-  ( ( ph /\ x e. I ) -> ( ( mulGrp o. R ) ` x ) = ( mulGrp ` ( R ` x ) ) ) | 
						
							| 12 | 11 | eqcomd |  |-  ( ( ph /\ x e. I ) -> ( mulGrp ` ( R ` x ) ) = ( ( mulGrp o. R ) ` x ) ) | 
						
							| 13 | 12 | fveq2d |  |-  ( ( ph /\ x e. I ) -> ( Base ` ( mulGrp ` ( R ` x ) ) ) = ( Base ` ( ( mulGrp o. R ) ` x ) ) ) | 
						
							| 14 | 9 13 | eqtrid |  |-  ( ( ph /\ x e. I ) -> ( Base ` ( R ` x ) ) = ( Base ` ( ( mulGrp o. R ) ` x ) ) ) | 
						
							| 15 | 14 | ixpeq2dva |  |-  ( ph -> X_ x e. I ( Base ` ( R ` x ) ) = X_ x e. I ( Base ` ( ( mulGrp o. R ) ` x ) ) ) | 
						
							| 16 |  | eqid |  |-  ( Base ` Y ) = ( Base ` Y ) | 
						
							| 17 | 2 16 | mgpbas |  |-  ( Base ` Y ) = ( Base ` M ) | 
						
							| 18 | 17 | eqcomi |  |-  ( Base ` M ) = ( Base ` Y ) | 
						
							| 19 | 1 18 5 4 6 | prdsbas2 |  |-  ( ph -> ( Base ` M ) = X_ x e. I ( Base ` ( R ` x ) ) ) | 
						
							| 20 |  | eqid |  |-  ( Base ` Z ) = ( Base ` Z ) | 
						
							| 21 |  | fnmgp |  |-  mulGrp Fn _V | 
						
							| 22 |  | ssv |  |-  ran R C_ _V | 
						
							| 23 | 22 | a1i |  |-  ( ph -> ran R C_ _V ) | 
						
							| 24 |  | fnco |  |-  ( ( mulGrp Fn _V /\ R Fn I /\ ran R C_ _V ) -> ( mulGrp o. R ) Fn I ) | 
						
							| 25 | 21 6 23 24 | mp3an2i |  |-  ( ph -> ( mulGrp o. R ) Fn I ) | 
						
							| 26 | 3 20 5 4 25 | prdsbas2 |  |-  ( ph -> ( Base ` Z ) = X_ x e. I ( Base ` ( ( mulGrp o. R ) ` x ) ) ) | 
						
							| 27 | 15 19 26 | 3eqtr4d |  |-  ( ph -> ( Base ` M ) = ( Base ` Z ) ) | 
						
							| 28 |  | eqid |  |-  ( .r ` Y ) = ( .r ` Y ) | 
						
							| 29 | 2 28 | mgpplusg |  |-  ( .r ` Y ) = ( +g ` M ) | 
						
							| 30 |  | eqid |  |-  ( mulGrp ` ( R ` z ) ) = ( mulGrp ` ( R ` z ) ) | 
						
							| 31 |  | eqid |  |-  ( .r ` ( R ` z ) ) = ( .r ` ( R ` z ) ) | 
						
							| 32 | 30 31 | mgpplusg |  |-  ( .r ` ( R ` z ) ) = ( +g ` ( mulGrp ` ( R ` z ) ) ) | 
						
							| 33 |  | fvco2 |  |-  ( ( R Fn I /\ z e. I ) -> ( ( mulGrp o. R ) ` z ) = ( mulGrp ` ( R ` z ) ) ) | 
						
							| 34 | 6 33 | sylan |  |-  ( ( ph /\ z e. I ) -> ( ( mulGrp o. R ) ` z ) = ( mulGrp ` ( R ` z ) ) ) | 
						
							| 35 | 34 | eqcomd |  |-  ( ( ph /\ z e. I ) -> ( mulGrp ` ( R ` z ) ) = ( ( mulGrp o. R ) ` z ) ) | 
						
							| 36 | 35 | fveq2d |  |-  ( ( ph /\ z e. I ) -> ( +g ` ( mulGrp ` ( R ` z ) ) ) = ( +g ` ( ( mulGrp o. R ) ` z ) ) ) | 
						
							| 37 | 32 36 | eqtrid |  |-  ( ( ph /\ z e. I ) -> ( .r ` ( R ` z ) ) = ( +g ` ( ( mulGrp o. R ) ` z ) ) ) | 
						
							| 38 | 37 | oveqd |  |-  ( ( ph /\ z e. I ) -> ( ( x ` z ) ( .r ` ( R ` z ) ) ( y ` z ) ) = ( ( x ` z ) ( +g ` ( ( mulGrp o. R ) ` z ) ) ( y ` z ) ) ) | 
						
							| 39 | 38 | mpteq2dva |  |-  ( ph -> ( z e. I |-> ( ( x ` z ) ( .r ` ( R ` z ) ) ( y ` z ) ) ) = ( z e. I |-> ( ( x ` z ) ( +g ` ( ( mulGrp o. R ) ` z ) ) ( y ` z ) ) ) ) | 
						
							| 40 | 27 27 39 | mpoeq123dv |  |-  ( ph -> ( x e. ( Base ` M ) , y e. ( Base ` M ) |-> ( z e. I |-> ( ( x ` z ) ( .r ` ( R ` z ) ) ( y ` z ) ) ) ) = ( x e. ( Base ` Z ) , y e. ( Base ` Z ) |-> ( z e. I |-> ( ( x ` z ) ( +g ` ( ( mulGrp o. R ) ` z ) ) ( y ` z ) ) ) ) ) | 
						
							| 41 |  | fnex |  |-  ( ( R Fn I /\ I e. V ) -> R e. _V ) | 
						
							| 42 | 6 4 41 | syl2anc |  |-  ( ph -> R e. _V ) | 
						
							| 43 | 6 | fndmd |  |-  ( ph -> dom R = I ) | 
						
							| 44 | 1 5 42 18 43 28 | prdsmulr |  |-  ( ph -> ( .r ` Y ) = ( x e. ( Base ` M ) , y e. ( Base ` M ) |-> ( z e. I |-> ( ( x ` z ) ( .r ` ( R ` z ) ) ( y ` z ) ) ) ) ) | 
						
							| 45 |  | fnex |  |-  ( ( ( mulGrp o. R ) Fn I /\ I e. V ) -> ( mulGrp o. R ) e. _V ) | 
						
							| 46 | 25 4 45 | syl2anc |  |-  ( ph -> ( mulGrp o. R ) e. _V ) | 
						
							| 47 | 25 | fndmd |  |-  ( ph -> dom ( mulGrp o. R ) = I ) | 
						
							| 48 |  | eqid |  |-  ( +g ` Z ) = ( +g ` Z ) | 
						
							| 49 | 3 5 46 20 47 48 | prdsplusg |  |-  ( ph -> ( +g ` Z ) = ( x e. ( Base ` Z ) , y e. ( Base ` Z ) |-> ( z e. I |-> ( ( x ` z ) ( +g ` ( ( mulGrp o. R ) ` z ) ) ( y ` z ) ) ) ) ) | 
						
							| 50 | 40 44 49 | 3eqtr4d |  |-  ( ph -> ( .r ` Y ) = ( +g ` Z ) ) | 
						
							| 51 | 29 50 | eqtr3id |  |-  ( ph -> ( +g ` M ) = ( +g ` Z ) ) | 
						
							| 52 | 27 51 | jca |  |-  ( ph -> ( ( Base ` M ) = ( Base ` Z ) /\ ( +g ` M ) = ( +g ` Z ) ) ) |