| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lssat.s |  | 
						
							| 2 |  | lssat.a |  | 
						
							| 3 |  | dfpss3 |  | 
						
							| 4 | 3 | simprbi |  | 
						
							| 5 |  | ss2rab |  | 
						
							| 6 |  | iman |  | 
						
							| 7 | 6 | ralbii |  | 
						
							| 8 | 5 7 | bitr2i |  | 
						
							| 9 |  | simpl1 |  | 
						
							| 10 | 1 2 | lsatlss |  | 
						
							| 11 |  | rabss2 |  | 
						
							| 12 |  | uniss |  | 
						
							| 13 | 9 10 11 12 | 4syl |  | 
						
							| 14 |  | simpl2 |  | 
						
							| 15 |  | unimax |  | 
						
							| 16 | 14 15 | syl |  | 
						
							| 17 |  | eqid |  | 
						
							| 18 | 17 1 | lssss |  | 
						
							| 19 | 14 18 | syl |  | 
						
							| 20 | 16 19 | eqsstrd |  | 
						
							| 21 | 13 20 | sstrd |  | 
						
							| 22 |  | uniss |  | 
						
							| 23 | 22 | adantl |  | 
						
							| 24 |  | eqid |  | 
						
							| 25 | 17 24 | lspss |  | 
						
							| 26 | 9 21 23 25 | syl3anc |  | 
						
							| 27 |  | simpl3 |  | 
						
							| 28 | 1 24 2 | lssats |  | 
						
							| 29 | 9 27 28 | syl2anc |  | 
						
							| 30 | 1 24 2 | lssats |  | 
						
							| 31 | 9 14 30 | syl2anc |  | 
						
							| 32 | 26 29 31 | 3sstr4d |  | 
						
							| 33 | 32 | ex |  | 
						
							| 34 | 8 33 | biimtrid |  | 
						
							| 35 | 34 | con3dimp |  | 
						
							| 36 |  | dfrex2 |  | 
						
							| 37 | 35 36 | sylibr |  | 
						
							| 38 | 4 37 | sylan2 |  |