| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mdsymlem1.1 |  | 
						
							| 2 |  | mdsymlem1.2 |  | 
						
							| 3 |  | mdsymlem1.3 |  | 
						
							| 4 | 2 | hatomici |  | 
						
							| 5 |  | simplll |  | 
						
							| 6 |  | atelch |  | 
						
							| 7 |  | atelch |  | 
						
							| 8 |  | chub1 |  | 
						
							| 9 | 6 7 8 | syl2an |  | 
						
							| 10 | 9 | adantlr |  | 
						
							| 11 | 10 | adantlr |  | 
						
							| 12 | 1 2 3 | mdsymlem1 |  | 
						
							| 13 | 6 12 | sylanl1 |  | 
						
							| 14 | 13 | adantr |  | 
						
							| 15 | 11 14 | jca |  | 
						
							| 16 | 15 | anim1i |  | 
						
							| 17 |  | anass |  | 
						
							| 18 | 16 17 | sylib |  | 
						
							| 19 | 18 | anasss |  | 
						
							| 20 |  | oveq1 |  | 
						
							| 21 | 20 | sseq2d |  | 
						
							| 22 |  | sseq1 |  | 
						
							| 23 | 22 | anbi1d |  | 
						
							| 24 | 21 23 | anbi12d |  | 
						
							| 25 | 24 | rspcev |  | 
						
							| 26 | 5 19 25 | syl2anc |  | 
						
							| 27 | 26 | exp32 |  | 
						
							| 28 | 27 | reximdvai |  | 
						
							| 29 | 4 28 | syl5 |  |