| Step | Hyp | Ref | Expression | 
						
							| 1 |  | idn1 |  | 
						
							| 2 |  | simp1 |  | 
						
							| 3 | 1 2 | e1a |  | 
						
							| 4 |  | simp2 |  | 
						
							| 5 | 1 4 | e1a |  | 
						
							| 6 |  | pm4.39 |  | 
						
							| 7 | 6 | ex |  | 
						
							| 8 | 3 5 7 | e11 |  | 
						
							| 9 |  | simp3 |  | 
						
							| 10 | 1 9 | e1a |  | 
						
							| 11 |  | pm4.39 |  | 
						
							| 12 | 11 | ex |  | 
						
							| 13 | 8 10 12 | e11 |  | 
						
							| 14 |  | df-3or |  | 
						
							| 15 | 14 | bicomi |  | 
						
							| 16 |  | bitr3 |  | 
						
							| 17 | 16 | com12 |  | 
						
							| 18 | 13 15 17 | e10 |  | 
						
							| 19 |  | df-3or |  | 
						
							| 20 | 19 | bicomi |  | 
						
							| 21 |  | bitr |  | 
						
							| 22 | 21 | ex |  | 
						
							| 23 | 18 20 22 | e10 |  | 
						
							| 24 | 23 | in1 |  |