| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpr |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> S = dom ( _om CNF X ) ) | 
						
							| 2 | 1 | eleq2d |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( F e. S <-> F e. dom ( _om CNF X ) ) ) | 
						
							| 3 |  | eqid |  |-  dom ( _om CNF X ) = dom ( _om CNF X ) | 
						
							| 4 |  | omelon |  |-  _om e. On | 
						
							| 5 | 4 | a1i |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> _om e. On ) | 
						
							| 6 |  | simpl |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> X e. On ) | 
						
							| 7 | 3 5 6 | cantnfs |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( F e. dom ( _om CNF X ) <-> ( F : X --> _om /\ F finSupp (/) ) ) ) | 
						
							| 8 | 2 7 | bitrd |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( F e. S <-> ( F : X --> _om /\ F finSupp (/) ) ) ) | 
						
							| 9 |  | simpl |  |-  ( ( F : X --> _om /\ F finSupp (/) ) -> F : X --> _om ) | 
						
							| 10 | 9 | ffnd |  |-  ( ( F : X --> _om /\ F finSupp (/) ) -> F Fn X ) | 
						
							| 11 | 8 10 | biimtrdi |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( F e. S -> F Fn X ) ) | 
						
							| 12 |  | simp1 |  |-  ( ( F e. S /\ G e. S /\ H e. S ) -> F e. S ) | 
						
							| 13 | 11 12 | impel |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> F Fn X ) | 
						
							| 14 | 1 | eleq2d |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( G e. S <-> G e. dom ( _om CNF X ) ) ) | 
						
							| 15 | 3 5 6 | cantnfs |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( G e. dom ( _om CNF X ) <-> ( G : X --> _om /\ G finSupp (/) ) ) ) | 
						
							| 16 | 14 15 | bitrd |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( G e. S <-> ( G : X --> _om /\ G finSupp (/) ) ) ) | 
						
							| 17 |  | simpl |  |-  ( ( G : X --> _om /\ G finSupp (/) ) -> G : X --> _om ) | 
						
							| 18 | 17 | ffnd |  |-  ( ( G : X --> _om /\ G finSupp (/) ) -> G Fn X ) | 
						
							| 19 | 16 18 | biimtrdi |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( G e. S -> G Fn X ) ) | 
						
							| 20 |  | simp2 |  |-  ( ( F e. S /\ G e. S /\ H e. S ) -> G e. S ) | 
						
							| 21 | 19 20 | impel |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> G Fn X ) | 
						
							| 22 | 6 | adantr |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> X e. On ) | 
						
							| 23 |  | inidm |  |-  ( X i^i X ) = X | 
						
							| 24 | 13 21 22 22 23 | offn |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> ( F oF +o G ) Fn X ) | 
						
							| 25 | 1 | eleq2d |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( H e. S <-> H e. dom ( _om CNF X ) ) ) | 
						
							| 26 | 3 5 6 | cantnfs |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( H e. dom ( _om CNF X ) <-> ( H : X --> _om /\ H finSupp (/) ) ) ) | 
						
							| 27 | 25 26 | bitrd |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( H e. S <-> ( H : X --> _om /\ H finSupp (/) ) ) ) | 
						
							| 28 |  | simpl |  |-  ( ( H : X --> _om /\ H finSupp (/) ) -> H : X --> _om ) | 
						
							| 29 | 28 | ffnd |  |-  ( ( H : X --> _om /\ H finSupp (/) ) -> H Fn X ) | 
						
							| 30 | 27 29 | biimtrdi |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( H e. S -> H Fn X ) ) | 
						
							| 31 |  | simp3 |  |-  ( ( F e. S /\ G e. S /\ H e. S ) -> H e. S ) | 
						
							| 32 | 30 31 | impel |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> H Fn X ) | 
						
							| 33 | 24 32 22 22 23 | offn |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> ( ( F oF +o G ) oF +o H ) Fn X ) | 
						
							| 34 | 21 32 22 22 23 | offn |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> ( G oF +o H ) Fn X ) | 
						
							| 35 | 13 34 22 22 23 | offn |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> ( F oF +o ( G oF +o H ) ) Fn X ) | 
						
							| 36 | 8 9 | biimtrdi |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( F e. S -> F : X --> _om ) ) | 
						
							| 37 | 36 12 | impel |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> F : X --> _om ) | 
						
							| 38 | 37 | ffvelcdmda |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( F ` x ) e. _om ) | 
						
							| 39 | 16 17 | biimtrdi |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( G e. S -> G : X --> _om ) ) | 
						
							| 40 | 39 20 | impel |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> G : X --> _om ) | 
						
							| 41 | 40 | ffvelcdmda |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( G ` x ) e. _om ) | 
						
							| 42 | 27 28 | biimtrdi |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( H e. S -> H : X --> _om ) ) | 
						
							| 43 | 42 31 | impel |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> H : X --> _om ) | 
						
							| 44 | 43 | ffvelcdmda |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( H ` x ) e. _om ) | 
						
							| 45 |  | nnaass |  |-  ( ( ( F ` x ) e. _om /\ ( G ` x ) e. _om /\ ( H ` x ) e. _om ) -> ( ( ( F ` x ) +o ( G ` x ) ) +o ( H ` x ) ) = ( ( F ` x ) +o ( ( G ` x ) +o ( H ` x ) ) ) ) | 
						
							| 46 | 38 41 44 45 | syl3anc |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( ( F ` x ) +o ( G ` x ) ) +o ( H ` x ) ) = ( ( F ` x ) +o ( ( G ` x ) +o ( H ` x ) ) ) ) | 
						
							| 47 | 13 | adantr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> F Fn X ) | 
						
							| 48 | 21 | adantr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> G Fn X ) | 
						
							| 49 | 22 | anim1i |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( X e. On /\ x e. X ) ) | 
						
							| 50 |  | fnfvof |  |-  ( ( ( F Fn X /\ G Fn X ) /\ ( X e. On /\ x e. X ) ) -> ( ( F oF +o G ) ` x ) = ( ( F ` x ) +o ( G ` x ) ) ) | 
						
							| 51 | 47 48 49 50 | syl21anc |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( F oF +o G ) ` x ) = ( ( F ` x ) +o ( G ` x ) ) ) | 
						
							| 52 | 51 | oveq1d |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( ( F oF +o G ) ` x ) +o ( H ` x ) ) = ( ( ( F ` x ) +o ( G ` x ) ) +o ( H ` x ) ) ) | 
						
							| 53 | 32 | adantr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> H Fn X ) | 
						
							| 54 |  | fnfvof |  |-  ( ( ( G Fn X /\ H Fn X ) /\ ( X e. On /\ x e. X ) ) -> ( ( G oF +o H ) ` x ) = ( ( G ` x ) +o ( H ` x ) ) ) | 
						
							| 55 | 48 53 49 54 | syl21anc |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( G oF +o H ) ` x ) = ( ( G ` x ) +o ( H ` x ) ) ) | 
						
							| 56 | 55 | oveq2d |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( F ` x ) +o ( ( G oF +o H ) ` x ) ) = ( ( F ` x ) +o ( ( G ` x ) +o ( H ` x ) ) ) ) | 
						
							| 57 | 46 52 56 | 3eqtr4d |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( ( F oF +o G ) ` x ) +o ( H ` x ) ) = ( ( F ` x ) +o ( ( G oF +o H ) ` x ) ) ) | 
						
							| 58 | 24 | adantr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( F oF +o G ) Fn X ) | 
						
							| 59 |  | fnfvof |  |-  ( ( ( ( F oF +o G ) Fn X /\ H Fn X ) /\ ( X e. On /\ x e. X ) ) -> ( ( ( F oF +o G ) oF +o H ) ` x ) = ( ( ( F oF +o G ) ` x ) +o ( H ` x ) ) ) | 
						
							| 60 | 58 53 49 59 | syl21anc |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( ( F oF +o G ) oF +o H ) ` x ) = ( ( ( F oF +o G ) ` x ) +o ( H ` x ) ) ) | 
						
							| 61 | 34 | adantr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( G oF +o H ) Fn X ) | 
						
							| 62 |  | fnfvof |  |-  ( ( ( F Fn X /\ ( G oF +o H ) Fn X ) /\ ( X e. On /\ x e. X ) ) -> ( ( F oF +o ( G oF +o H ) ) ` x ) = ( ( F ` x ) +o ( ( G oF +o H ) ` x ) ) ) | 
						
							| 63 | 47 61 49 62 | syl21anc |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( F oF +o ( G oF +o H ) ) ` x ) = ( ( F ` x ) +o ( ( G oF +o H ) ` x ) ) ) | 
						
							| 64 | 57 60 63 | 3eqtr4d |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) /\ x e. X ) -> ( ( ( F oF +o G ) oF +o H ) ` x ) = ( ( F oF +o ( G oF +o H ) ) ` x ) ) | 
						
							| 65 | 33 35 64 | eqfnfvd |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( F e. S /\ G e. S /\ H e. S ) ) -> ( ( F oF +o G ) oF +o H ) = ( F oF +o ( G oF +o H ) ) ) |