| Step | Hyp | Ref | Expression | 
						
							| 1 |  | suppssof1.s |  | 
						
							| 2 |  | suppssof1.o |  | 
						
							| 3 |  | suppssof1.a |  | 
						
							| 4 |  | suppssof1.b |  | 
						
							| 5 |  | suppssof1.d |  | 
						
							| 6 |  | suppssof1.y |  | 
						
							| 7 | 3 | ffnd |  | 
						
							| 8 | 4 | ffnd |  | 
						
							| 9 |  | inidm |  | 
						
							| 10 |  | eqidd |  | 
						
							| 11 |  | eqidd |  | 
						
							| 12 | 7 8 5 5 9 10 11 | offval |  | 
						
							| 13 | 12 | oveq1d |  | 
						
							| 14 | 3 | feqmptd |  | 
						
							| 15 | 14 | oveq1d |  | 
						
							| 16 | 15 1 | eqsstrrd |  | 
						
							| 17 |  | fvexd |  | 
						
							| 18 | 4 | ffvelcdmda |  | 
						
							| 19 | 16 2 17 18 6 | suppssov1 |  | 
						
							| 20 | 13 19 | eqsstrd |  |