| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rrxmval.1 |  |-  X = { h e. ( RR ^m I ) | h finSupp 0 } | 
						
							| 2 |  | simprl |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) -> ( F ` x ) = 0 ) | 
						
							| 3 |  | 0cn |  |-  0 e. CC | 
						
							| 4 | 2 3 | eqeltrdi |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) -> ( F ` x ) e. CC ) | 
						
							| 5 |  | simprr |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) -> ( G ` x ) = 0 ) | 
						
							| 6 | 2 5 | eqtr4d |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) -> ( F ` x ) = ( G ` x ) ) | 
						
							| 7 | 4 6 | subeq0bd |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) -> ( ( F ` x ) - ( G ` x ) ) = 0 ) | 
						
							| 8 | 7 | sq0id |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) -> ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) = 0 ) | 
						
							| 9 | 8 | ex |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) -> ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) = 0 ) ) | 
						
							| 10 |  | ioran |  |-  ( -. ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) <-> ( -. ( F ` x ) =/= 0 /\ -. ( G ` x ) =/= 0 ) ) | 
						
							| 11 |  | nne |  |-  ( -. ( F ` x ) =/= 0 <-> ( F ` x ) = 0 ) | 
						
							| 12 |  | nne |  |-  ( -. ( G ` x ) =/= 0 <-> ( G ` x ) = 0 ) | 
						
							| 13 | 11 12 | anbi12i |  |-  ( ( -. ( F ` x ) =/= 0 /\ -. ( G ` x ) =/= 0 ) <-> ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) | 
						
							| 14 | 10 13 | bitri |  |-  ( -. ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) <-> ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) | 
						
							| 15 | 14 | a1i |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( -. ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) <-> ( ( F ` x ) = 0 /\ ( G ` x ) = 0 ) ) ) | 
						
							| 16 |  | eqidd |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) = ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ) | 
						
							| 17 |  | simpr |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ k = x ) -> k = x ) | 
						
							| 18 | 17 | fveq2d |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ k = x ) -> ( F ` k ) = ( F ` x ) ) | 
						
							| 19 | 17 | fveq2d |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ k = x ) -> ( G ` k ) = ( G ` x ) ) | 
						
							| 20 | 18 19 | oveq12d |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ k = x ) -> ( ( F ` k ) - ( G ` k ) ) = ( ( F ` x ) - ( G ` x ) ) ) | 
						
							| 21 | 20 | oveq1d |  |-  ( ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) /\ k = x ) -> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) = ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) ) | 
						
							| 22 |  | simpr |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> x e. I ) | 
						
							| 23 |  | ovex |  |-  ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) e. _V | 
						
							| 24 | 23 | a1i |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) e. _V ) | 
						
							| 25 | 16 21 22 24 | fvmptd |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) = ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) ) | 
						
							| 26 | 25 | neeq1d |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 <-> ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) =/= 0 ) ) | 
						
							| 27 | 26 | bicomd |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) =/= 0 <-> ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 ) ) | 
						
							| 28 | 27 | necon1bbid |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( -. ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 <-> ( ( ( F ` x ) - ( G ` x ) ) ^ 2 ) = 0 ) ) | 
						
							| 29 | 9 15 28 | 3imtr4d |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( -. ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) -> -. ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 ) ) | 
						
							| 30 | 29 | con4d |  |-  ( ( ( I e. V /\ F e. X /\ G e. X ) /\ x e. I ) -> ( ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 -> ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) ) ) | 
						
							| 31 | 30 | ss2rabdv |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> { x e. I | ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 } C_ { x e. I | ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) } ) | 
						
							| 32 |  | unrab |  |-  ( { x e. I | ( F ` x ) =/= 0 } u. { x e. I | ( G ` x ) =/= 0 } ) = { x e. I | ( ( F ` x ) =/= 0 \/ ( G ` x ) =/= 0 ) } | 
						
							| 33 | 31 32 | sseqtrrdi |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> { x e. I | ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 } C_ ( { x e. I | ( F ` x ) =/= 0 } u. { x e. I | ( G ` x ) =/= 0 } ) ) | 
						
							| 34 |  | simp1 |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> I e. V ) | 
						
							| 35 |  | ovex |  |-  ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) e. _V | 
						
							| 36 |  | eqid |  |-  ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) = ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) | 
						
							| 37 | 35 36 | fnmpti |  |-  ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) Fn I | 
						
							| 38 |  | suppvalfn |  |-  ( ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) Fn I /\ I e. V /\ 0 e. CC ) -> ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) supp 0 ) = { x e. I | ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 } ) | 
						
							| 39 | 37 3 38 | mp3an13 |  |-  ( I e. V -> ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) supp 0 ) = { x e. I | ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 } ) | 
						
							| 40 | 34 39 | syl |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) supp 0 ) = { x e. I | ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) ` x ) =/= 0 } ) | 
						
							| 41 |  | elrabi |  |-  ( F e. { h e. ( RR ^m I ) | h finSupp 0 } -> F e. ( RR ^m I ) ) | 
						
							| 42 | 41 1 | eleq2s |  |-  ( F e. X -> F e. ( RR ^m I ) ) | 
						
							| 43 |  | elmapi |  |-  ( F e. ( RR ^m I ) -> F : I --> RR ) | 
						
							| 44 |  | ffn |  |-  ( F : I --> RR -> F Fn I ) | 
						
							| 45 | 42 43 44 | 3syl |  |-  ( F e. X -> F Fn I ) | 
						
							| 46 | 45 | 3ad2ant2 |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> F Fn I ) | 
						
							| 47 | 3 | a1i |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> 0 e. CC ) | 
						
							| 48 |  | suppvalfn |  |-  ( ( F Fn I /\ I e. V /\ 0 e. CC ) -> ( F supp 0 ) = { x e. I | ( F ` x ) =/= 0 } ) | 
						
							| 49 | 46 34 47 48 | syl3anc |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> ( F supp 0 ) = { x e. I | ( F ` x ) =/= 0 } ) | 
						
							| 50 |  | elrabi |  |-  ( G e. { h e. ( RR ^m I ) | h finSupp 0 } -> G e. ( RR ^m I ) ) | 
						
							| 51 | 50 1 | eleq2s |  |-  ( G e. X -> G e. ( RR ^m I ) ) | 
						
							| 52 |  | elmapi |  |-  ( G e. ( RR ^m I ) -> G : I --> RR ) | 
						
							| 53 |  | ffn |  |-  ( G : I --> RR -> G Fn I ) | 
						
							| 54 | 51 52 53 | 3syl |  |-  ( G e. X -> G Fn I ) | 
						
							| 55 | 54 | 3ad2ant3 |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> G Fn I ) | 
						
							| 56 |  | suppvalfn |  |-  ( ( G Fn I /\ I e. V /\ 0 e. CC ) -> ( G supp 0 ) = { x e. I | ( G ` x ) =/= 0 } ) | 
						
							| 57 | 55 34 47 56 | syl3anc |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> ( G supp 0 ) = { x e. I | ( G ` x ) =/= 0 } ) | 
						
							| 58 | 49 57 | uneq12d |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> ( ( F supp 0 ) u. ( G supp 0 ) ) = ( { x e. I | ( F ` x ) =/= 0 } u. { x e. I | ( G ` x ) =/= 0 } ) ) | 
						
							| 59 | 33 40 58 | 3sstr4d |  |-  ( ( I e. V /\ F e. X /\ G e. X ) -> ( ( k e. I |-> ( ( ( F ` k ) - ( G ` k ) ) ^ 2 ) ) supp 0 ) C_ ( ( F supp 0 ) u. ( G supp 0 ) ) ) |