| 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 | 1 | eleq2d |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( g e. S <-> g e. dom ( _om CNF X ) ) ) | 
						
							| 10 | 3 5 6 | cantnfs |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( g e. dom ( _om CNF X ) <-> ( g : X --> _om /\ g finSupp (/) ) ) ) | 
						
							| 11 | 9 10 | bitrd |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( g e. S <-> ( g : X --> _om /\ g finSupp (/) ) ) ) | 
						
							| 12 | 11 | adantr |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) -> ( g e. S <-> ( g : X --> _om /\ g finSupp (/) ) ) ) | 
						
							| 13 |  | simpl |  |-  ( ( f : X --> _om /\ f finSupp (/) ) -> f : X --> _om ) | 
						
							| 14 |  | simpl |  |-  ( ( g : X --> _om /\ g finSupp (/) ) -> g : X --> _om ) | 
						
							| 15 | 13 14 | anim12i |  |-  ( ( ( f : X --> _om /\ f finSupp (/) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( f : X --> _om /\ g : X --> _om ) ) | 
						
							| 16 | 6 15 | anim12i |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( ( f : X --> _om /\ f finSupp (/) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) ) -> ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) ) | 
						
							| 17 | 16 | anassrs |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) ) | 
						
							| 18 |  | simprl |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> f : X --> _om ) | 
						
							| 19 | 18 | ffnd |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> f Fn X ) | 
						
							| 20 |  | simprr |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> g : X --> _om ) | 
						
							| 21 | 20 | ffnd |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> g Fn X ) | 
						
							| 22 |  | simpl |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> X e. On ) | 
						
							| 23 |  | inidm |  |-  ( X i^i X ) = X | 
						
							| 24 | 19 21 22 22 23 | offn |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> ( f oF +o g ) Fn X ) | 
						
							| 25 |  | simpr |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ ( f oF +o g ) Fn X ) -> ( f oF +o g ) Fn X ) | 
						
							| 26 |  | simplrl |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> f : X --> _om ) | 
						
							| 27 | 26 | ffnd |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> f Fn X ) | 
						
							| 28 |  | simplrr |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> g : X --> _om ) | 
						
							| 29 | 28 | ffnd |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> g Fn X ) | 
						
							| 30 |  | simpll |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> X e. On ) | 
						
							| 31 |  | simpr |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> x e. X ) | 
						
							| 32 |  | fnfvof |  |-  ( ( ( f Fn X /\ g Fn X ) /\ ( X e. On /\ x e. X ) ) -> ( ( f oF +o g ) ` x ) = ( ( f ` x ) +o ( g ` x ) ) ) | 
						
							| 33 | 27 29 30 31 32 | syl22anc |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> ( ( f oF +o g ) ` x ) = ( ( f ` x ) +o ( g ` x ) ) ) | 
						
							| 34 | 18 | ffvelcdmda |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> ( f ` x ) e. _om ) | 
						
							| 35 | 20 | ffvelcdmda |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> ( g ` x ) e. _om ) | 
						
							| 36 |  | nnacl |  |-  ( ( ( f ` x ) e. _om /\ ( g ` x ) e. _om ) -> ( ( f ` x ) +o ( g ` x ) ) e. _om ) | 
						
							| 37 | 34 35 36 | syl2anc |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> ( ( f ` x ) +o ( g ` x ) ) e. _om ) | 
						
							| 38 | 33 37 | eqeltrd |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ x e. X ) -> ( ( f oF +o g ) ` x ) e. _om ) | 
						
							| 39 | 38 | ex |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> ( x e. X -> ( ( f oF +o g ) ` x ) e. _om ) ) | 
						
							| 40 | 39 | ralrimiv |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> A. x e. X ( ( f oF +o g ) ` x ) e. _om ) | 
						
							| 41 | 40 | adantr |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ ( f oF +o g ) Fn X ) -> A. x e. X ( ( f oF +o g ) ` x ) e. _om ) | 
						
							| 42 |  | fnfvrnss |  |-  ( ( ( f oF +o g ) Fn X /\ A. x e. X ( ( f oF +o g ) ` x ) e. _om ) -> ran ( f oF +o g ) C_ _om ) | 
						
							| 43 | 25 41 42 | syl2anc |  |-  ( ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) /\ ( f oF +o g ) Fn X ) -> ran ( f oF +o g ) C_ _om ) | 
						
							| 44 | 43 | ex |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> ( ( f oF +o g ) Fn X -> ran ( f oF +o g ) C_ _om ) ) | 
						
							| 45 | 24 44 | jcai |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> ( ( f oF +o g ) Fn X /\ ran ( f oF +o g ) C_ _om ) ) | 
						
							| 46 |  | df-f |  |-  ( ( f oF +o g ) : X --> _om <-> ( ( f oF +o g ) Fn X /\ ran ( f oF +o g ) C_ _om ) ) | 
						
							| 47 | 45 46 | sylibr |  |-  ( ( X e. On /\ ( f : X --> _om /\ g : X --> _om ) ) -> ( f oF +o g ) : X --> _om ) | 
						
							| 48 | 17 47 | syl |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( f oF +o g ) : X --> _om ) | 
						
							| 49 |  | ffun |  |-  ( ( f oF +o g ) : X --> _om -> Fun ( f oF +o g ) ) | 
						
							| 50 | 49 | adantl |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> Fun ( f oF +o g ) ) | 
						
							| 51 |  | simplrr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> f finSupp (/) ) | 
						
							| 52 | 51 | adantr |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> f finSupp (/) ) | 
						
							| 53 |  | simplrr |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> g finSupp (/) ) | 
						
							| 54 | 52 53 | fsuppunfi |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( ( f supp (/) ) u. ( g supp (/) ) ) e. Fin ) | 
						
							| 55 |  | simp-4l |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> X e. On ) | 
						
							| 56 |  | peano1 |  |-  (/) e. _om | 
						
							| 57 | 56 | a1i |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> (/) e. _om ) | 
						
							| 58 |  | simplrl |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> f : X --> _om ) | 
						
							| 59 | 58 | adantr |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> f : X --> _om ) | 
						
							| 60 |  | simplrl |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> g : X --> _om ) | 
						
							| 61 |  | 0elon |  |-  (/) e. On | 
						
							| 62 |  | oa0 |  |-  ( (/) e. On -> ( (/) +o (/) ) = (/) ) | 
						
							| 63 | 61 62 | mp1i |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( (/) +o (/) ) = (/) ) | 
						
							| 64 | 55 57 59 60 63 | suppofssd |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( ( f oF +o g ) supp (/) ) C_ ( ( f supp (/) ) u. ( g supp (/) ) ) ) | 
						
							| 65 | 54 64 | ssfid |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( ( f oF +o g ) supp (/) ) e. Fin ) | 
						
							| 66 |  | ovexd |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( f oF +o g ) e. _V ) | 
						
							| 67 |  | isfsupp |  |-  ( ( ( f oF +o g ) e. _V /\ (/) e. On ) -> ( ( f oF +o g ) finSupp (/) <-> ( Fun ( f oF +o g ) /\ ( ( f oF +o g ) supp (/) ) e. Fin ) ) ) | 
						
							| 68 | 66 61 67 | sylancl |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( ( f oF +o g ) finSupp (/) <-> ( Fun ( f oF +o g ) /\ ( ( f oF +o g ) supp (/) ) e. Fin ) ) ) | 
						
							| 69 | 50 65 68 | mpbir2and |  |-  ( ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) /\ ( f oF +o g ) : X --> _om ) -> ( f oF +o g ) finSupp (/) ) | 
						
							| 70 | 69 | ex |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( ( f oF +o g ) : X --> _om -> ( f oF +o g ) finSupp (/) ) ) | 
						
							| 71 | 48 70 | jcai |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( ( f oF +o g ) : X --> _om /\ ( f oF +o g ) finSupp (/) ) ) | 
						
							| 72 | 1 | eleq2d |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( ( f oF +o g ) e. S <-> ( f oF +o g ) e. dom ( _om CNF X ) ) ) | 
						
							| 73 | 3 5 6 | cantnfs |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( ( f oF +o g ) e. dom ( _om CNF X ) <-> ( ( f oF +o g ) : X --> _om /\ ( f oF +o g ) finSupp (/) ) ) ) | 
						
							| 74 | 72 73 | bitrd |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( ( f oF +o g ) e. S <-> ( ( f oF +o g ) : X --> _om /\ ( f oF +o g ) finSupp (/) ) ) ) | 
						
							| 75 | 74 | ad2antrr |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( ( f oF +o g ) e. S <-> ( ( f oF +o g ) : X --> _om /\ ( f oF +o g ) finSupp (/) ) ) ) | 
						
							| 76 | 71 75 | mpbird |  |-  ( ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) /\ ( g : X --> _om /\ g finSupp (/) ) ) -> ( f oF +o g ) e. S ) | 
						
							| 77 | 76 | ex |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) -> ( ( g : X --> _om /\ g finSupp (/) ) -> ( f oF +o g ) e. S ) ) | 
						
							| 78 | 12 77 | sylbid |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) -> ( g e. S -> ( f oF +o g ) e. S ) ) | 
						
							| 79 | 78 | ralrimiv |  |-  ( ( ( X e. On /\ S = dom ( _om CNF X ) ) /\ ( f : X --> _om /\ f finSupp (/) ) ) -> A. g e. S ( f oF +o g ) e. S ) | 
						
							| 80 | 79 | ex |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( ( f : X --> _om /\ f finSupp (/) ) -> A. g e. S ( f oF +o g ) e. S ) ) | 
						
							| 81 | 8 80 | sylbid |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( f e. S -> A. g e. S ( f oF +o g ) e. S ) ) | 
						
							| 82 | 81 | ralrimiv |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> A. f e. S A. g e. S ( f oF +o g ) e. S ) | 
						
							| 83 |  | ofmres |  |-  ( oF +o |` ( S X. S ) ) = ( f e. S , g e. S |-> ( f oF +o g ) ) | 
						
							| 84 | 83 | fmpo |  |-  ( A. f e. S A. g e. S ( f oF +o g ) e. S <-> ( oF +o |` ( S X. S ) ) : ( S X. S ) --> S ) | 
						
							| 85 | 82 84 | sylib |  |-  ( ( X e. On /\ S = dom ( _om CNF X ) ) -> ( oF +o |` ( S X. S ) ) : ( S X. S ) --> S ) |