| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fsplitfpar.h |  |-  H = ( ( `' ( 1st |` ( _V X. _V ) ) o. ( F o. ( 1st |` ( _V X. _V ) ) ) ) i^i ( `' ( 2nd |` ( _V X. _V ) ) o. ( G o. ( 2nd |` ( _V X. _V ) ) ) ) ) | 
						
							| 2 |  | fsplitfpar.s |  |-  S = ( `' ( 1st |` _I ) |` A ) | 
						
							| 3 | 1 2 | fsplitfpar |  |-  ( ( F Fn A /\ G Fn A ) -> ( H o. S ) = ( a e. A |-> <. ( F ` a ) , ( G ` a ) >. ) ) | 
						
							| 4 | 3 | coeq2d |  |-  ( ( F Fn A /\ G Fn A ) -> ( .+ o. ( H o. S ) ) = ( .+ o. ( a e. A |-> <. ( F ` a ) , ( G ` a ) >. ) ) ) | 
						
							| 5 | 4 | 3ad2ant1 |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> ( .+ o. ( H o. S ) ) = ( .+ o. ( a e. A |-> <. ( F ` a ) , ( G ` a ) >. ) ) ) | 
						
							| 6 |  | dffn3 |  |-  ( .+ Fn C <-> .+ : C --> ran .+ ) | 
						
							| 7 | 6 | biimpi |  |-  ( .+ Fn C -> .+ : C --> ran .+ ) | 
						
							| 8 | 7 | adantr |  |-  ( ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) -> .+ : C --> ran .+ ) | 
						
							| 9 | 8 | 3ad2ant3 |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> .+ : C --> ran .+ ) | 
						
							| 10 |  | simpl3r |  |-  ( ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) /\ a e. A ) -> ( ran F X. ran G ) C_ C ) | 
						
							| 11 |  | simp1l |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> F Fn A ) | 
						
							| 12 |  | fnfvelrn |  |-  ( ( F Fn A /\ a e. A ) -> ( F ` a ) e. ran F ) | 
						
							| 13 | 11 12 | sylan |  |-  ( ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) /\ a e. A ) -> ( F ` a ) e. ran F ) | 
						
							| 14 |  | simp1r |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> G Fn A ) | 
						
							| 15 |  | fnfvelrn |  |-  ( ( G Fn A /\ a e. A ) -> ( G ` a ) e. ran G ) | 
						
							| 16 | 14 15 | sylan |  |-  ( ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) /\ a e. A ) -> ( G ` a ) e. ran G ) | 
						
							| 17 | 13 16 | opelxpd |  |-  ( ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) /\ a e. A ) -> <. ( F ` a ) , ( G ` a ) >. e. ( ran F X. ran G ) ) | 
						
							| 18 | 10 17 | sseldd |  |-  ( ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) /\ a e. A ) -> <. ( F ` a ) , ( G ` a ) >. e. C ) | 
						
							| 19 | 9 18 | cofmpt |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> ( .+ o. ( a e. A |-> <. ( F ` a ) , ( G ` a ) >. ) ) = ( a e. A |-> ( .+ ` <. ( F ` a ) , ( G ` a ) >. ) ) ) | 
						
							| 20 |  | df-ov |  |-  ( ( F ` a ) .+ ( G ` a ) ) = ( .+ ` <. ( F ` a ) , ( G ` a ) >. ) | 
						
							| 21 | 20 | eqcomi |  |-  ( .+ ` <. ( F ` a ) , ( G ` a ) >. ) = ( ( F ` a ) .+ ( G ` a ) ) | 
						
							| 22 | 21 | mpteq2i |  |-  ( a e. A |-> ( .+ ` <. ( F ` a ) , ( G ` a ) >. ) ) = ( a e. A |-> ( ( F ` a ) .+ ( G ` a ) ) ) | 
						
							| 23 | 19 22 | eqtrdi |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> ( .+ o. ( a e. A |-> <. ( F ` a ) , ( G ` a ) >. ) ) = ( a e. A |-> ( ( F ` a ) .+ ( G ` a ) ) ) ) | 
						
							| 24 |  | offval3 |  |-  ( ( F e. V /\ G e. W ) -> ( F oF .+ G ) = ( a e. ( dom F i^i dom G ) |-> ( ( F ` a ) .+ ( G ` a ) ) ) ) | 
						
							| 25 |  | fndm |  |-  ( F Fn A -> dom F = A ) | 
						
							| 26 |  | fndm |  |-  ( G Fn A -> dom G = A ) | 
						
							| 27 | 25 26 | ineqan12d |  |-  ( ( F Fn A /\ G Fn A ) -> ( dom F i^i dom G ) = ( A i^i A ) ) | 
						
							| 28 |  | inidm |  |-  ( A i^i A ) = A | 
						
							| 29 | 27 28 | eqtrdi |  |-  ( ( F Fn A /\ G Fn A ) -> ( dom F i^i dom G ) = A ) | 
						
							| 30 | 29 | mpteq1d |  |-  ( ( F Fn A /\ G Fn A ) -> ( a e. ( dom F i^i dom G ) |-> ( ( F ` a ) .+ ( G ` a ) ) ) = ( a e. A |-> ( ( F ` a ) .+ ( G ` a ) ) ) ) | 
						
							| 31 | 24 30 | sylan9eqr |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) ) -> ( F oF .+ G ) = ( a e. A |-> ( ( F ` a ) .+ ( G ` a ) ) ) ) | 
						
							| 32 | 31 | eqcomd |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) ) -> ( a e. A |-> ( ( F ` a ) .+ ( G ` a ) ) ) = ( F oF .+ G ) ) | 
						
							| 33 | 32 | 3adant3 |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> ( a e. A |-> ( ( F ` a ) .+ ( G ` a ) ) ) = ( F oF .+ G ) ) | 
						
							| 34 | 5 23 33 | 3eqtrd |  |-  ( ( ( F Fn A /\ G Fn A ) /\ ( F e. V /\ G e. W ) /\ ( .+ Fn C /\ ( ran F X. ran G ) C_ C ) ) -> ( .+ o. ( H o. S ) ) = ( F oF .+ G ) ) |