| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dihlatat.a |  | 
						
							| 2 |  | dihlatat.h |  | 
						
							| 3 |  | dihlatat.u |  | 
						
							| 4 |  | dihlatat.i |  | 
						
							| 5 |  | dihlatat.l |  | 
						
							| 6 |  | id |  | 
						
							| 7 | 2 3 6 | dvhlvec |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 |  | eqid |  | 
						
							| 10 |  | eqid |  | 
						
							| 11 | 8 9 10 5 | islsat |  | 
						
							| 12 | 7 11 | syl |  | 
						
							| 13 | 12 | biimpa |  | 
						
							| 14 |  | eldifsn |  | 
						
							| 15 | 1 2 3 8 10 9 4 | dihlspsnat |  | 
						
							| 16 | 15 | 3expb |  | 
						
							| 17 | 14 16 | sylan2b |  | 
						
							| 18 |  | fveq2 |  | 
						
							| 19 | 18 | eleq1d |  | 
						
							| 20 | 17 19 | syl5ibrcom |  | 
						
							| 21 | 20 | rexlimdva |  | 
						
							| 22 | 21 | adantr |  | 
						
							| 23 | 13 22 | mpd |  |