| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fsuppssov1.s |  |-  ( ph -> ( x e. D |-> A ) finSupp Y ) | 
						
							| 2 |  | fsuppssov1.o |  |-  ( ( ph /\ v e. R ) -> ( Y O v ) = Z ) | 
						
							| 3 |  | fsuppssov1.a |  |-  ( ( ph /\ x e. D ) -> A e. V ) | 
						
							| 4 |  | fsuppssov1.b |  |-  ( ( ph /\ x e. D ) -> B e. R ) | 
						
							| 5 |  | fsuppssov1.z |  |-  ( ph -> Z e. W ) | 
						
							| 6 |  | relfsupp |  |-  Rel finSupp | 
						
							| 7 | 6 | brrelex1i |  |-  ( ( x e. D |-> A ) finSupp Y -> ( x e. D |-> A ) e. _V ) | 
						
							| 8 | 1 7 | syl |  |-  ( ph -> ( x e. D |-> A ) e. _V ) | 
						
							| 9 | 3 | fmpttd |  |-  ( ph -> ( x e. D |-> A ) : D --> V ) | 
						
							| 10 |  | dmfex |  |-  ( ( ( x e. D |-> A ) e. _V /\ ( x e. D |-> A ) : D --> V ) -> D e. _V ) | 
						
							| 11 | 8 9 10 | syl2anc |  |-  ( ph -> D e. _V ) | 
						
							| 12 | 11 | mptexd |  |-  ( ph -> ( x e. D |-> ( A O B ) ) e. _V ) | 
						
							| 13 |  | funmpt |  |-  Fun ( x e. D |-> ( A O B ) ) | 
						
							| 14 | 13 | a1i |  |-  ( ph -> Fun ( x e. D |-> ( A O B ) ) ) | 
						
							| 15 |  | ssidd |  |-  ( ph -> ( ( x e. D |-> A ) supp Y ) C_ ( ( x e. D |-> A ) supp Y ) ) | 
						
							| 16 | 6 | brrelex2i |  |-  ( ( x e. D |-> A ) finSupp Y -> Y e. _V ) | 
						
							| 17 | 1 16 | syl |  |-  ( ph -> Y e. _V ) | 
						
							| 18 | 15 2 3 4 17 | suppssov1 |  |-  ( ph -> ( ( x e. D |-> ( A O B ) ) supp Z ) C_ ( ( x e. D |-> A ) supp Y ) ) | 
						
							| 19 | 12 5 14 1 18 | fsuppsssuppgd |  |-  ( ph -> ( x e. D |-> ( A O B ) ) finSupp Z ) |