| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapfien.s |  |-  S = { x e. ( B ^m A ) | x finSupp Z } | 
						
							| 2 |  | mapfien.t |  |-  T = { x e. ( D ^m C ) | x finSupp W } | 
						
							| 3 |  | mapfien.w |  |-  W = ( G ` Z ) | 
						
							| 4 |  | mapfien.f |  |-  ( ph -> F : C -1-1-onto-> A ) | 
						
							| 5 |  | mapfien.g |  |-  ( ph -> G : B -1-1-onto-> D ) | 
						
							| 6 |  | mapfien.a |  |-  ( ph -> A e. U ) | 
						
							| 7 |  | mapfien.b |  |-  ( ph -> B e. V ) | 
						
							| 8 |  | mapfien.c |  |-  ( ph -> C e. X ) | 
						
							| 9 |  | mapfien.d |  |-  ( ph -> D e. Y ) | 
						
							| 10 |  | mapfien.z |  |-  ( ph -> Z e. B ) | 
						
							| 11 | 3 | fvexi |  |-  W e. _V | 
						
							| 12 | 11 | a1i |  |-  ( ( ph /\ f e. S ) -> W e. _V ) | 
						
							| 13 | 10 | adantr |  |-  ( ( ph /\ f e. S ) -> Z e. B ) | 
						
							| 14 |  | elrabi |  |-  ( f e. { x e. ( B ^m A ) | x finSupp Z } -> f e. ( B ^m A ) ) | 
						
							| 15 |  | elmapi |  |-  ( f e. ( B ^m A ) -> f : A --> B ) | 
						
							| 16 | 14 15 | syl |  |-  ( f e. { x e. ( B ^m A ) | x finSupp Z } -> f : A --> B ) | 
						
							| 17 | 16 1 | eleq2s |  |-  ( f e. S -> f : A --> B ) | 
						
							| 18 |  | f1of |  |-  ( F : C -1-1-onto-> A -> F : C --> A ) | 
						
							| 19 | 4 18 | syl |  |-  ( ph -> F : C --> A ) | 
						
							| 20 |  | fco |  |-  ( ( f : A --> B /\ F : C --> A ) -> ( f o. F ) : C --> B ) | 
						
							| 21 | 17 19 20 | syl2anr |  |-  ( ( ph /\ f e. S ) -> ( f o. F ) : C --> B ) | 
						
							| 22 |  | f1of |  |-  ( G : B -1-1-onto-> D -> G : B --> D ) | 
						
							| 23 | 5 22 | syl |  |-  ( ph -> G : B --> D ) | 
						
							| 24 | 23 | adantr |  |-  ( ( ph /\ f e. S ) -> G : B --> D ) | 
						
							| 25 |  | ssidd |  |-  ( ( ph /\ f e. S ) -> B C_ B ) | 
						
							| 26 | 8 | adantr |  |-  ( ( ph /\ f e. S ) -> C e. X ) | 
						
							| 27 | 7 | adantr |  |-  ( ( ph /\ f e. S ) -> B e. V ) | 
						
							| 28 |  | breq1 |  |-  ( x = f -> ( x finSupp Z <-> f finSupp Z ) ) | 
						
							| 29 | 28 1 | elrab2 |  |-  ( f e. S <-> ( f e. ( B ^m A ) /\ f finSupp Z ) ) | 
						
							| 30 | 29 | simprbi |  |-  ( f e. S -> f finSupp Z ) | 
						
							| 31 | 30 | adantl |  |-  ( ( ph /\ f e. S ) -> f finSupp Z ) | 
						
							| 32 |  | f1of1 |  |-  ( F : C -1-1-onto-> A -> F : C -1-1-> A ) | 
						
							| 33 | 4 32 | syl |  |-  ( ph -> F : C -1-1-> A ) | 
						
							| 34 | 33 | adantr |  |-  ( ( ph /\ f e. S ) -> F : C -1-1-> A ) | 
						
							| 35 |  | simpr |  |-  ( ( ph /\ f e. S ) -> f e. S ) | 
						
							| 36 | 31 34 13 35 | fsuppco |  |-  ( ( ph /\ f e. S ) -> ( f o. F ) finSupp Z ) | 
						
							| 37 | 3 | eqcomi |  |-  ( G ` Z ) = W | 
						
							| 38 | 37 | a1i |  |-  ( ( ph /\ f e. S ) -> ( G ` Z ) = W ) | 
						
							| 39 | 12 13 21 24 25 26 27 36 38 | fsuppcor |  |-  ( ( ph /\ f e. S ) -> ( G o. ( f o. F ) ) finSupp W ) |