| Step | Hyp | Ref | Expression | 
						
							| 1 |  | h1de2ct.1 |  | 
						
							| 2 |  | snssi |  | 
						
							| 3 |  | occl |  | 
						
							| 4 | 1 2 3 | mp2b |  | 
						
							| 5 | 4 | choccli |  | 
						
							| 6 | 5 | cheli |  | 
						
							| 7 |  | hvmulcl |  | 
						
							| 8 | 1 7 | mpan2 |  | 
						
							| 9 |  | eleq1 |  | 
						
							| 10 | 8 9 | syl5ibrcom |  | 
						
							| 11 | 10 | rexlimiv |  | 
						
							| 12 |  | eleq1 |  | 
						
							| 13 |  | eqeq1 |  | 
						
							| 14 | 13 | rexbidv |  | 
						
							| 15 | 12 14 | bibi12d |  | 
						
							| 16 |  | ifhvhv0 |  | 
						
							| 17 | 16 1 | h1de2ctlem |  | 
						
							| 18 | 15 17 | dedth |  | 
						
							| 19 | 6 11 18 | pm5.21nii |  |