| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pwsexpg.y |  |-  Y = ( R ^s I ) | 
						
							| 2 |  | pwsexpg.b |  |-  B = ( Base ` Y ) | 
						
							| 3 |  | pwsexpg.m |  |-  M = ( mulGrp ` Y ) | 
						
							| 4 |  | pwsexpg.t |  |-  T = ( mulGrp ` R ) | 
						
							| 5 |  | pwsexpg.s |  |-  .xb = ( .g ` M ) | 
						
							| 6 |  | pwsexpg.g |  |-  .x. = ( .g ` T ) | 
						
							| 7 |  | pwsexpg.r |  |-  ( ph -> R e. Ring ) | 
						
							| 8 |  | pwsexpg.i |  |-  ( ph -> I e. V ) | 
						
							| 9 |  | pwsexpg.n |  |-  ( ph -> N e. NN0 ) | 
						
							| 10 |  | pwsexpg.x |  |-  ( ph -> X e. B ) | 
						
							| 11 |  | pwsexpg.a |  |-  ( ph -> A e. I ) | 
						
							| 12 | 1 2 3 4 7 8 11 | pwspjmhmmgpd |  |-  ( ph -> ( x e. B |-> ( x ` A ) ) e. ( M MndHom T ) ) | 
						
							| 13 | 3 2 | mgpbas |  |-  B = ( Base ` M ) | 
						
							| 14 | 13 5 6 | mhmmulg |  |-  ( ( ( x e. B |-> ( x ` A ) ) e. ( M MndHom T ) /\ N e. NN0 /\ X e. B ) -> ( ( x e. B |-> ( x ` A ) ) ` ( N .xb X ) ) = ( N .x. ( ( x e. B |-> ( x ` A ) ) ` X ) ) ) | 
						
							| 15 | 12 9 10 14 | syl3anc |  |-  ( ph -> ( ( x e. B |-> ( x ` A ) ) ` ( N .xb X ) ) = ( N .x. ( ( x e. B |-> ( x ` A ) ) ` X ) ) ) | 
						
							| 16 | 1 | pwsring |  |-  ( ( R e. Ring /\ I e. V ) -> Y e. Ring ) | 
						
							| 17 | 7 8 16 | syl2anc |  |-  ( ph -> Y e. Ring ) | 
						
							| 18 | 3 | ringmgp |  |-  ( Y e. Ring -> M e. Mnd ) | 
						
							| 19 | 17 18 | syl |  |-  ( ph -> M e. Mnd ) | 
						
							| 20 | 13 5 19 9 10 | mulgnn0cld |  |-  ( ph -> ( N .xb X ) e. B ) | 
						
							| 21 |  | fveq1 |  |-  ( x = ( N .xb X ) -> ( x ` A ) = ( ( N .xb X ) ` A ) ) | 
						
							| 22 |  | eqid |  |-  ( x e. B |-> ( x ` A ) ) = ( x e. B |-> ( x ` A ) ) | 
						
							| 23 |  | fvex |  |-  ( ( N .xb X ) ` A ) e. _V | 
						
							| 24 | 21 22 23 | fvmpt |  |-  ( ( N .xb X ) e. B -> ( ( x e. B |-> ( x ` A ) ) ` ( N .xb X ) ) = ( ( N .xb X ) ` A ) ) | 
						
							| 25 | 20 24 | syl |  |-  ( ph -> ( ( x e. B |-> ( x ` A ) ) ` ( N .xb X ) ) = ( ( N .xb X ) ` A ) ) | 
						
							| 26 |  | fveq1 |  |-  ( x = X -> ( x ` A ) = ( X ` A ) ) | 
						
							| 27 |  | fvex |  |-  ( X ` A ) e. _V | 
						
							| 28 | 26 22 27 | fvmpt |  |-  ( X e. B -> ( ( x e. B |-> ( x ` A ) ) ` X ) = ( X ` A ) ) | 
						
							| 29 | 10 28 | syl |  |-  ( ph -> ( ( x e. B |-> ( x ` A ) ) ` X ) = ( X ` A ) ) | 
						
							| 30 | 29 | oveq2d |  |-  ( ph -> ( N .x. ( ( x e. B |-> ( x ` A ) ) ` X ) ) = ( N .x. ( X ` A ) ) ) | 
						
							| 31 | 15 25 30 | 3eqtr3d |  |-  ( ph -> ( ( N .xb X ) ` A ) = ( N .x. ( X ` A ) ) ) |