| Step | Hyp | Ref | Expression | 
						
							| 1 |  | psseq1 |  | 
						
							| 2 |  | oveq1 |  | 
						
							| 3 | 2 | sseq2d |  | 
						
							| 4 | 1 3 | anbi12d |  | 
						
							| 5 | 2 | eqeq2d |  | 
						
							| 6 | 4 5 | imbi12d |  | 
						
							| 7 |  | psseq2 |  | 
						
							| 8 |  | sseq1 |  | 
						
							| 9 | 7 8 | anbi12d |  | 
						
							| 10 |  | eqeq1 |  | 
						
							| 11 | 9 10 | imbi12d |  | 
						
							| 12 |  | sneq |  | 
						
							| 13 | 12 | fveq2d |  | 
						
							| 14 | 13 | oveq2d |  | 
						
							| 15 | 14 | sseq2d |  | 
						
							| 16 | 15 | anbi2d |  | 
						
							| 17 | 14 | eqeq2d |  | 
						
							| 18 | 16 17 | imbi12d |  | 
						
							| 19 |  | ifchhv |  | 
						
							| 20 |  | ifchhv |  | 
						
							| 21 |  | ifhvhv0 |  | 
						
							| 22 | 19 20 21 | spansncvi |  | 
						
							| 23 | 6 11 18 22 | dedth3h |  |