| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fargshift.g |  |-  G = ( x e. ( 0 ..^ ( # ` F ) ) |-> ( F ` ( x + 1 ) ) ) | 
						
							| 2 |  | fz0add1fz1 |  |-  ( ( N e. NN0 /\ l e. ( 0 ..^ N ) ) -> ( l + 1 ) e. ( 1 ... N ) ) | 
						
							| 3 |  | simpl |  |-  ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) -> ( l + 1 ) e. ( 1 ... N ) ) | 
						
							| 4 | 3 | adantr |  |-  ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) -> ( l + 1 ) e. ( 1 ... N ) ) | 
						
							| 5 |  | 2fveq3 |  |-  ( k = ( l + 1 ) -> ( E ` ( F ` k ) ) = ( E ` ( F ` ( l + 1 ) ) ) ) | 
						
							| 6 |  | csbeq1 |  |-  ( k = ( l + 1 ) -> [_ k / x ]_ P = [_ ( l + 1 ) / x ]_ P ) | 
						
							| 7 | 5 6 | eqeq12d |  |-  ( k = ( l + 1 ) -> ( ( E ` ( F ` k ) ) = [_ k / x ]_ P <-> ( E ` ( F ` ( l + 1 ) ) ) = [_ ( l + 1 ) / x ]_ P ) ) | 
						
							| 8 | 7 | adantl |  |-  ( ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) /\ k = ( l + 1 ) ) -> ( ( E ` ( F ` k ) ) = [_ k / x ]_ P <-> ( E ` ( F ` ( l + 1 ) ) ) = [_ ( l + 1 ) / x ]_ P ) ) | 
						
							| 9 |  | simpl |  |-  ( ( N e. NN0 /\ l e. ( 0 ..^ N ) ) -> N e. NN0 ) | 
						
							| 10 | 9 | adantl |  |-  ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) -> N e. NN0 ) | 
						
							| 11 | 10 | anim1i |  |-  ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) -> ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) ) | 
						
							| 12 | 11 | adantr |  |-  ( ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) /\ k = ( l + 1 ) ) -> ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) ) | 
						
							| 13 |  | simpr |  |-  ( ( N e. NN0 /\ l e. ( 0 ..^ N ) ) -> l e. ( 0 ..^ N ) ) | 
						
							| 14 | 13 | ad3antlr |  |-  ( ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) /\ k = ( l + 1 ) ) -> l e. ( 0 ..^ N ) ) | 
						
							| 15 | 1 | fargshiftfv |  |-  ( ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) -> ( l e. ( 0 ..^ N ) -> ( G ` l ) = ( F ` ( l + 1 ) ) ) ) | 
						
							| 16 | 15 | imp |  |-  ( ( ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) /\ l e. ( 0 ..^ N ) ) -> ( G ` l ) = ( F ` ( l + 1 ) ) ) | 
						
							| 17 | 16 | eqcomd |  |-  ( ( ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) /\ l e. ( 0 ..^ N ) ) -> ( F ` ( l + 1 ) ) = ( G ` l ) ) | 
						
							| 18 | 12 14 17 | syl2anc |  |-  ( ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) /\ k = ( l + 1 ) ) -> ( F ` ( l + 1 ) ) = ( G ` l ) ) | 
						
							| 19 | 18 | fveqeq2d |  |-  ( ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) /\ k = ( l + 1 ) ) -> ( ( E ` ( F ` ( l + 1 ) ) ) = [_ ( l + 1 ) / x ]_ P <-> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) | 
						
							| 20 | 8 19 | bitrd |  |-  ( ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) /\ k = ( l + 1 ) ) -> ( ( E ` ( F ` k ) ) = [_ k / x ]_ P <-> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) | 
						
							| 21 | 4 20 | rspcdv |  |-  ( ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) /\ F : ( 1 ... N ) --> dom E ) -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) | 
						
							| 22 | 21 | ex |  |-  ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) -> ( F : ( 1 ... N ) --> dom E -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) ) | 
						
							| 23 | 22 | com23 |  |-  ( ( ( l + 1 ) e. ( 1 ... N ) /\ ( N e. NN0 /\ l e. ( 0 ..^ N ) ) ) -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> ( F : ( 1 ... N ) --> dom E -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) ) | 
						
							| 24 | 2 23 | mpancom |  |-  ( ( N e. NN0 /\ l e. ( 0 ..^ N ) ) -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> ( F : ( 1 ... N ) --> dom E -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) ) | 
						
							| 25 | 24 | ex |  |-  ( N e. NN0 -> ( l e. ( 0 ..^ N ) -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> ( F : ( 1 ... N ) --> dom E -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) ) ) | 
						
							| 26 | 25 | com24 |  |-  ( N e. NN0 -> ( F : ( 1 ... N ) --> dom E -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> ( l e. ( 0 ..^ N ) -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) ) ) | 
						
							| 27 | 26 | imp31 |  |-  ( ( ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) /\ A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P ) -> ( l e. ( 0 ..^ N ) -> ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) | 
						
							| 28 | 27 | ralrimiv |  |-  ( ( ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) /\ A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P ) -> A. l e. ( 0 ..^ N ) ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) | 
						
							| 29 | 28 | ex |  |-  ( ( N e. NN0 /\ F : ( 1 ... N ) --> dom E ) -> ( A. k e. ( 1 ... N ) ( E ` ( F ` k ) ) = [_ k / x ]_ P -> A. l e. ( 0 ..^ N ) ( E ` ( G ` l ) ) = [_ ( l + 1 ) / x ]_ P ) ) |