| Step | Hyp | Ref | Expression | 
						
							| 1 |  | islvol2a.l |  | 
						
							| 2 |  | islvol2a.j |  | 
						
							| 3 |  | islvol2a.a |  | 
						
							| 4 |  | islvol2a.v |  | 
						
							| 5 |  | oveq1 |  | 
						
							| 6 |  | simpl1 |  | 
						
							| 7 |  | simpl3 |  | 
						
							| 8 | 2 3 | hlatjidm |  | 
						
							| 9 | 6 7 8 | syl2anc |  | 
						
							| 10 | 5 9 | sylan9eqr |  | 
						
							| 11 | 10 | oveq1d |  | 
						
							| 12 | 11 | oveq1d |  | 
						
							| 13 |  | simprl |  | 
						
							| 14 |  | simprr |  | 
						
							| 15 | 2 3 4 | 3atnelvolN |  | 
						
							| 16 | 6 7 13 14 15 | syl13anc |  | 
						
							| 17 | 16 | adantr |  | 
						
							| 18 | 12 17 | eqneltrd |  | 
						
							| 19 | 18 | ex |  | 
						
							| 20 | 19 | necon2ad |  | 
						
							| 21 | 6 | hllatd |  | 
						
							| 22 |  | eqid |  | 
						
							| 23 | 22 3 | atbase |  | 
						
							| 24 | 23 | ad2antrl |  | 
						
							| 25 | 22 2 3 | hlatjcl |  | 
						
							| 26 | 25 | adantr |  | 
						
							| 27 | 22 1 2 | latleeqj2 |  | 
						
							| 28 | 21 24 26 27 | syl3anc |  | 
						
							| 29 |  | simpl2 |  | 
						
							| 30 | 2 3 4 | 3atnelvolN |  | 
						
							| 31 | 6 29 7 14 30 | syl13anc |  | 
						
							| 32 |  | oveq1 |  | 
						
							| 33 | 32 | eleq1d |  | 
						
							| 34 | 33 | notbid |  | 
						
							| 35 | 31 34 | syl5ibrcom |  | 
						
							| 36 | 28 35 | sylbid |  | 
						
							| 37 | 36 | con2d |  | 
						
							| 38 | 22 3 | atbase |  | 
						
							| 39 | 38 | ad2antll |  | 
						
							| 40 | 22 2 | latjcl |  | 
						
							| 41 | 21 26 24 40 | syl3anc |  | 
						
							| 42 | 22 1 2 | latleeqj2 |  | 
						
							| 43 | 21 39 41 42 | syl3anc |  | 
						
							| 44 | 2 3 4 | 3atnelvolN |  | 
						
							| 45 | 6 29 7 13 44 | syl13anc |  | 
						
							| 46 |  | eleq1 |  | 
						
							| 47 | 46 | notbid |  | 
						
							| 48 | 45 47 | syl5ibrcom |  | 
						
							| 49 | 43 48 | sylbid |  | 
						
							| 50 | 49 | con2d |  | 
						
							| 51 | 20 37 50 | 3jcad |  | 
						
							| 52 | 1 2 3 4 | lvoli2 |  | 
						
							| 53 | 52 | 3expia |  | 
						
							| 54 | 51 53 | impbid |  |