| Step | Hyp | Ref | Expression | 
						
							| 1 |  | marypha2lem.t |  | 
						
							| 2 |  | dffn5 |  | 
						
							| 3 | 2 | biimpi |  | 
						
							| 4 | 3 | adantl |  | 
						
							| 5 |  | df-mpt |  | 
						
							| 6 | 4 5 | eqtrdi |  | 
						
							| 7 | 1 | marypha2lem2 |  | 
						
							| 8 | 7 | a1i |  | 
						
							| 9 | 6 8 | sseq12d |  | 
						
							| 10 |  | ssopab2bw |  | 
						
							| 11 | 9 10 | bitrdi |  | 
						
							| 12 |  | 19.21v |  | 
						
							| 13 |  | imdistan |  | 
						
							| 14 | 13 | albii |  | 
						
							| 15 |  | fvex |  | 
						
							| 16 |  | eleq1 |  | 
						
							| 17 | 15 16 | ceqsalv |  | 
						
							| 18 | 17 | imbi2i |  | 
						
							| 19 | 12 14 18 | 3bitr3i |  | 
						
							| 20 | 19 | albii |  | 
						
							| 21 |  | df-ral |  | 
						
							| 22 | 20 21 | bitr4i |  | 
						
							| 23 | 11 22 | bitrdi |  |