| Step | Hyp | Ref | Expression | 
						
							| 1 |  | om2noseq.1 |  |-  ( ph -> C e. No ) | 
						
							| 2 |  | om2noseq.2 |  |-  ( ph -> G = ( rec ( ( x e. _V |-> ( x +s 1s ) ) , C ) |` _om ) ) | 
						
							| 3 |  | om2noseq.3 |  |-  ( ph -> Z = ( rec ( ( x e. _V |-> ( x +s 1s ) ) , C ) " _om ) ) | 
						
							| 4 | 1 2 3 | om2noseqlt |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( A e. B -> ( G ` A )  | 
						
							| 5 | 1 2 3 | om2noseqlt |  |-  ( ( ph /\ ( B e. _om /\ A e. _om ) ) -> ( B e. A -> ( G ` B )  | 
						
							| 6 | 5 | ancom2s |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( B e. A -> ( G ` B )  | 
						
							| 7 |  | fveq2 |  |-  ( B = A -> ( G ` B ) = ( G ` A ) ) | 
						
							| 8 | 7 | a1i |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( B = A -> ( G ` B ) = ( G ` A ) ) ) | 
						
							| 9 | 6 8 | orim12d |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( ( B e. A \/ B = A ) -> ( ( G ` B )  | 
						
							| 10 |  | nnon |  |-  ( B e. _om -> B e. On ) | 
						
							| 11 |  | nnon |  |-  ( A e. _om -> A e. On ) | 
						
							| 12 |  | onsseleq |  |-  ( ( B e. On /\ A e. On ) -> ( B C_ A <-> ( B e. A \/ B = A ) ) ) | 
						
							| 13 |  | ontri1 |  |-  ( ( B e. On /\ A e. On ) -> ( B C_ A <-> -. A e. B ) ) | 
						
							| 14 | 12 13 | bitr3d |  |-  ( ( B e. On /\ A e. On ) -> ( ( B e. A \/ B = A ) <-> -. A e. B ) ) | 
						
							| 15 | 10 11 14 | syl2anr |  |-  ( ( A e. _om /\ B e. _om ) -> ( ( B e. A \/ B = A ) <-> -. A e. B ) ) | 
						
							| 16 | 15 | adantl |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( ( B e. A \/ B = A ) <-> -. A e. B ) ) | 
						
							| 17 | 1 2 3 | om2noseqfo |  |-  ( ph -> G : _om -onto-> Z ) | 
						
							| 18 |  | fof |  |-  ( G : _om -onto-> Z -> G : _om --> Z ) | 
						
							| 19 | 17 18 | syl |  |-  ( ph -> G : _om --> Z ) | 
						
							| 20 | 3 1 | noseqssno |  |-  ( ph -> Z C_ No ) | 
						
							| 21 | 19 20 | fssd |  |-  ( ph -> G : _om --> No ) | 
						
							| 22 | 21 | ffvelcdmda |  |-  ( ( ph /\ B e. _om ) -> ( G ` B ) e. No ) | 
						
							| 23 | 22 | adantrl |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( G ` B ) e. No ) | 
						
							| 24 | 21 | ffvelcdmda |  |-  ( ( ph /\ A e. _om ) -> ( G ` A ) e. No ) | 
						
							| 25 | 24 | adantrr |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( G ` A ) e. No ) | 
						
							| 26 |  | sleloe |  |-  ( ( ( G ` B ) e. No /\ ( G ` A ) e. No ) -> ( ( G ` B ) <_s ( G ` A ) <-> ( ( G ` B )  | 
						
							| 27 |  | slenlt |  |-  ( ( ( G ` B ) e. No /\ ( G ` A ) e. No ) -> ( ( G ` B ) <_s ( G ` A ) <-> -. ( G ` A )  | 
						
							| 28 | 26 27 | bitr3d |  |-  ( ( ( G ` B ) e. No /\ ( G ` A ) e. No ) -> ( ( ( G ` B )  -. ( G ` A )  | 
						
							| 29 | 23 25 28 | syl2anc |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( ( ( G ` B )  -. ( G ` A )  | 
						
							| 30 | 9 16 29 | 3imtr3d |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( -. A e. B -> -. ( G ` A )  | 
						
							| 31 | 4 30 | impcon4bid |  |-  ( ( ph /\ ( A e. _om /\ B e. _om ) ) -> ( A e. B <-> ( G ` A )  |