| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpr |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> E = ( _om ^o D ) ) | 
						
							| 2 |  | omelon |  |-  _om e. On | 
						
							| 3 |  | simpl |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> D e. On ) | 
						
							| 4 |  | oecl |  |-  ( ( _om e. On /\ D e. On ) -> ( _om ^o D ) e. On ) | 
						
							| 5 | 2 3 4 | sylancr |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> ( _om ^o D ) e. On ) | 
						
							| 6 | 1 5 | eqeltrd |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> E e. On ) | 
						
							| 7 | 3 2 | jctil |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> ( _om e. On /\ D e. On ) ) | 
						
							| 8 |  | peano1 |  |-  (/) e. _om | 
						
							| 9 |  | oen0 |  |-  ( ( ( _om e. On /\ D e. On ) /\ (/) e. _om ) -> (/) e. ( _om ^o D ) ) | 
						
							| 10 | 7 8 9 | sylancl |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> (/) e. ( _om ^o D ) ) | 
						
							| 11 | 10 1 | eleqtrrd |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> (/) e. E ) | 
						
							| 12 |  | oveq1 |  |-  ( x = (/) -> ( x +o E ) = ( (/) +o E ) ) | 
						
							| 13 | 12 | sseq2d |  |-  ( x = (/) -> ( E C_ ( x +o E ) <-> E C_ ( (/) +o E ) ) ) | 
						
							| 14 | 13 | adantl |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x = (/) ) -> ( E C_ ( x +o E ) <-> E C_ ( (/) +o E ) ) ) | 
						
							| 15 |  | oa0r |  |-  ( E e. On -> ( (/) +o E ) = E ) | 
						
							| 16 | 6 15 | syl |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> ( (/) +o E ) = E ) | 
						
							| 17 |  | ssid |  |-  ( (/) +o E ) C_ ( (/) +o E ) | 
						
							| 18 | 16 17 | eqsstrrdi |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> E C_ ( (/) +o E ) ) | 
						
							| 19 | 11 14 18 | rspcedvd |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> E. x e. E E C_ ( x +o E ) ) | 
						
							| 20 |  | ssiun |  |-  ( E. x e. E E C_ ( x +o E ) -> E C_ U_ x e. E ( x +o E ) ) | 
						
							| 21 | 19 20 | syl |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> E C_ U_ x e. E ( x +o E ) ) | 
						
							| 22 | 1 | eleq2d |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> ( x e. E <-> x e. ( _om ^o D ) ) ) | 
						
							| 23 | 22 | biimpa |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x e. E ) -> x e. ( _om ^o D ) ) | 
						
							| 24 | 6 | adantr |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x e. E ) -> E e. On ) | 
						
							| 25 | 1 | adantr |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x e. E ) -> E = ( _om ^o D ) ) | 
						
							| 26 |  | ssid |  |-  E C_ E | 
						
							| 27 | 25 26 | eqsstrrdi |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x e. E ) -> ( _om ^o D ) C_ E ) | 
						
							| 28 |  | oaabs2 |  |-  ( ( ( x e. ( _om ^o D ) /\ E e. On ) /\ ( _om ^o D ) C_ E ) -> ( x +o E ) = E ) | 
						
							| 29 | 23 24 27 28 | syl21anc |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x e. E ) -> ( x +o E ) = E ) | 
						
							| 30 | 29 26 | eqsstrdi |  |-  ( ( ( D e. On /\ E = ( _om ^o D ) ) /\ x e. E ) -> ( x +o E ) C_ E ) | 
						
							| 31 | 30 | iunssd |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> U_ x e. E ( x +o E ) C_ E ) | 
						
							| 32 | 21 31 | eqssd |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> E = U_ x e. E ( x +o E ) ) | 
						
							| 33 | 6 6 32 | 3jca |  |-  ( ( D e. On /\ E = ( _om ^o D ) ) -> ( E e. On /\ E e. On /\ E = U_ x e. E ( x +o E ) ) ) | 
						
							| 34 |  | ofoafg |  |-  ( ( ( A e. V /\ B e. W /\ C = ( A i^i B ) ) /\ ( E e. On /\ E e. On /\ E = U_ x e. E ( x +o E ) ) ) -> ( oF +o |` ( ( E ^m A ) X. ( E ^m B ) ) ) : ( ( E ^m A ) X. ( E ^m B ) ) --> ( E ^m C ) ) | 
						
							| 35 | 33 34 | sylan2 |  |-  ( ( ( A e. V /\ B e. W /\ C = ( A i^i B ) ) /\ ( D e. On /\ E = ( _om ^o D ) ) ) -> ( oF +o |` ( ( E ^m A ) X. ( E ^m B ) ) ) : ( ( E ^m A ) X. ( E ^m B ) ) --> ( E ^m C ) ) |