| Step | Hyp | Ref | Expression | 
						
							| 1 |  | om2noseq.1 |  | 
						
							| 2 |  | om2noseq.2 |  | 
						
							| 3 |  | om2noseq.3 |  | 
						
							| 4 | 1 2 3 | om2noseqlt |  | 
						
							| 5 | 1 2 3 | om2noseqlt |  | 
						
							| 6 | 5 | ancom2s |  | 
						
							| 7 |  | fveq2 |  | 
						
							| 8 | 7 | a1i |  | 
						
							| 9 | 6 8 | orim12d |  | 
						
							| 10 |  | nnon |  | 
						
							| 11 |  | nnon |  | 
						
							| 12 |  | onsseleq |  | 
						
							| 13 |  | ontri1 |  | 
						
							| 14 | 12 13 | bitr3d |  | 
						
							| 15 | 10 11 14 | syl2anr |  | 
						
							| 16 | 15 | adantl |  | 
						
							| 17 | 1 2 3 | om2noseqfo |  | 
						
							| 18 |  | fof |  | 
						
							| 19 | 17 18 | syl |  | 
						
							| 20 | 3 1 | noseqssno |  | 
						
							| 21 | 19 20 | fssd |  | 
						
							| 22 | 21 | ffvelcdmda |  | 
						
							| 23 | 22 | adantrl |  | 
						
							| 24 | 21 | ffvelcdmda |  | 
						
							| 25 | 24 | adantrr |  | 
						
							| 26 |  | sleloe |  | 
						
							| 27 |  | slenlt |  | 
						
							| 28 | 26 27 | bitr3d |  | 
						
							| 29 | 23 25 28 | syl2anc |  | 
						
							| 30 | 9 16 29 | 3imtr3d |  | 
						
							| 31 | 4 30 | impcon4bid |  |