| Step | Hyp | Ref | Expression | 
						
							| 1 |  | imass2 |  | 
						
							| 2 | 1 | unissd |  | 
						
							| 3 | 2 | sspwd |  | 
						
							| 4 | 3 | adantl |  | 
						
							| 5 | 4 | adantl |  | 
						
							| 6 |  | ssrexv |  | 
						
							| 7 | 5 6 | syl |  | 
						
							| 8 |  | ssrexv |  | 
						
							| 9 | 5 8 | syl |  | 
						
							| 10 | 9 | reximdv |  | 
						
							| 11 | 7 10 | syld |  | 
						
							| 12 | 11 | adantr |  | 
						
							| 13 | 12 | ss2rabdv |  | 
						
							| 14 |  | madeval2 |  | 
						
							| 15 | 14 | adantr |  | 
						
							| 16 |  | madeval2 |  | 
						
							| 17 | 16 | adantr |  | 
						
							| 18 | 17 | adantl |  | 
						
							| 19 | 13 15 18 | 3sstr4d |  | 
						
							| 20 |  | madef |  | 
						
							| 21 | 20 | fdmi |  | 
						
							| 22 | 21 | eleq2i |  | 
						
							| 23 |  | ndmfv |  | 
						
							| 24 | 22 23 | sylnbir |  | 
						
							| 25 |  | 0ss |  | 
						
							| 26 | 24 25 | eqsstrdi |  | 
						
							| 27 | 26 | adantr |  | 
						
							| 28 | 19 27 | pm2.61ian |  |