| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ldilcnv.h |  | 
						
							| 2 |  | ldilcnv.d |  | 
						
							| 3 |  | simpll |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 | 1 4 2 | ldillaut |  | 
						
							| 6 | 4 | lautcnv |  | 
						
							| 7 | 3 5 6 | syl2anc |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 |  | eqid |  | 
						
							| 10 | 8 9 1 2 | ldilval |  | 
						
							| 11 | 10 | 3expa |  | 
						
							| 12 | 11 | 3impb |  | 
						
							| 13 | 12 | fveq2d |  | 
						
							| 14 | 8 1 2 | ldil1o |  | 
						
							| 15 | 14 | 3ad2ant1 |  | 
						
							| 16 |  | simp2 |  | 
						
							| 17 |  | f1ocnvfv1 |  | 
						
							| 18 | 15 16 17 | syl2anc |  | 
						
							| 19 | 13 18 | eqtr3d |  | 
						
							| 20 | 19 | 3exp |  | 
						
							| 21 | 20 | ralrimiv |  | 
						
							| 22 | 8 9 1 4 2 | isldil |  | 
						
							| 23 | 22 | adantr |  | 
						
							| 24 | 7 21 23 | mpbir2and |  |