| Step | Hyp | Ref | Expression | 
						
							| 1 |  | islssfg.x |  | 
						
							| 2 |  | islssfg.s |  | 
						
							| 3 |  | islssfg.n |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 | 4 2 | lssss |  | 
						
							| 6 | 1 4 | ressbas2 |  | 
						
							| 7 | 5 6 | syl |  | 
						
							| 8 | 7 | pweqd |  | 
						
							| 9 | 8 | rexeqdv |  | 
						
							| 10 | 9 | adantl |  | 
						
							| 11 |  | elpwi |  | 
						
							| 12 |  | eqid |  | 
						
							| 13 | 1 3 12 2 | lsslsp |  | 
						
							| 14 | 13 | 3expa |  | 
						
							| 15 | 11 14 | sylan2 |  | 
						
							| 16 | 15 | eqcomd |  | 
						
							| 17 | 7 | ad2antlr |  | 
						
							| 18 | 16 17 | eqeq12d |  | 
						
							| 19 | 18 | anbi2d |  | 
						
							| 20 | 19 | rexbidva |  | 
						
							| 21 | 1 2 | lsslmod |  | 
						
							| 22 |  | eqid |  | 
						
							| 23 | 22 12 | islmodfg |  | 
						
							| 24 | 21 23 | syl |  | 
						
							| 25 | 10 20 24 | 3bitr4rd |  |