| Step | Hyp | Ref | Expression | 
						
							| 1 |  | spansn |  | 
						
							| 2 | 1 | eleq2d |  | 
						
							| 3 | 2 | 3ad2ant2 |  | 
						
							| 4 |  | eleq1 |  | 
						
							| 5 |  | id |  | 
						
							| 6 |  | oveq1 |  | 
						
							| 7 | 6 | oveq1d |  | 
						
							| 8 | 7 | oveq1d |  | 
						
							| 9 | 5 8 | eqeq12d |  | 
						
							| 10 | 4 9 | bibi12d |  | 
						
							| 11 | 10 | imbi2d |  | 
						
							| 12 |  | neeq1 |  | 
						
							| 13 |  | sneq |  | 
						
							| 14 | 13 | fveq2d |  | 
						
							| 15 | 14 | fveq2d |  | 
						
							| 16 | 15 | eleq2d |  | 
						
							| 17 |  | oveq2 |  | 
						
							| 18 |  | oveq1 |  | 
						
							| 19 |  | oveq2 |  | 
						
							| 20 | 18 19 | eqtrd |  | 
						
							| 21 | 17 20 | oveq12d |  | 
						
							| 22 |  | id |  | 
						
							| 23 | 21 22 | oveq12d |  | 
						
							| 24 | 23 | eqeq2d |  | 
						
							| 25 | 16 24 | bibi12d |  | 
						
							| 26 | 12 25 | imbi12d |  | 
						
							| 27 |  | ifhvhv0 |  | 
						
							| 28 |  | ifhvhv0 |  | 
						
							| 29 | 27 28 | h1de2bi |  | 
						
							| 30 | 11 26 29 | dedth2h |  | 
						
							| 31 | 30 | 3impia |  | 
						
							| 32 | 3 31 | bitrd |  |