| Step | Hyp | Ref | Expression | 
						
							| 1 |  | catccatid.c |  | 
						
							| 2 |  | catccatid.b |  | 
						
							| 3 | 2 | a1i |  | 
						
							| 4 |  | eqidd |  | 
						
							| 5 |  | eqidd |  | 
						
							| 6 | 1 | fvexi |  | 
						
							| 7 | 6 | a1i |  | 
						
							| 8 |  | biid |  | 
						
							| 9 |  | id |  | 
						
							| 10 | 1 2 9 | catcbas |  | 
						
							| 11 |  | inss2 |  | 
						
							| 12 | 10 11 | eqsstrdi |  | 
						
							| 13 | 12 | sselda |  | 
						
							| 14 |  | eqid |  | 
						
							| 15 | 14 | idfucl |  | 
						
							| 16 | 13 15 | syl |  | 
						
							| 17 |  | simpl |  | 
						
							| 18 |  | eqid |  | 
						
							| 19 |  | simpr |  | 
						
							| 20 | 1 2 17 18 19 19 | catchom |  | 
						
							| 21 | 16 20 | eleqtrrd |  | 
						
							| 22 |  | simpl |  | 
						
							| 23 |  | eqid |  | 
						
							| 24 |  | simpr1l |  | 
						
							| 25 |  | simpr1r |  | 
						
							| 26 |  | simpr31 |  | 
						
							| 27 | 1 2 22 18 24 25 | catchom |  | 
						
							| 28 | 26 27 | eleqtrd |  | 
						
							| 29 | 25 16 | syldan |  | 
						
							| 30 | 1 2 22 23 24 25 25 28 29 | catcco |  | 
						
							| 31 | 28 14 | cofulid |  | 
						
							| 32 | 30 31 | eqtrd |  | 
						
							| 33 |  | simpr2l |  | 
						
							| 34 |  | simpr32 |  | 
						
							| 35 | 1 2 22 18 25 33 | catchom |  | 
						
							| 36 | 34 35 | eleqtrd |  | 
						
							| 37 | 1 2 22 23 25 25 33 29 36 | catcco |  | 
						
							| 38 | 36 14 | cofurid |  | 
						
							| 39 | 37 38 | eqtrd |  | 
						
							| 40 | 28 36 | cofucl |  | 
						
							| 41 | 1 2 22 23 24 25 33 28 36 | catcco |  | 
						
							| 42 | 1 2 22 18 24 33 | catchom |  | 
						
							| 43 | 40 41 42 | 3eltr4d |  | 
						
							| 44 |  | simpr33 |  | 
						
							| 45 |  | simpr2r |  | 
						
							| 46 | 1 2 22 18 33 45 | catchom |  | 
						
							| 47 | 44 46 | eleqtrd |  | 
						
							| 48 | 28 36 47 | cofuass |  | 
						
							| 49 | 36 47 | cofucl |  | 
						
							| 50 | 1 2 22 23 24 25 45 28 49 | catcco |  | 
						
							| 51 | 1 2 22 23 24 33 45 40 47 | catcco |  | 
						
							| 52 | 48 50 51 | 3eqtr4d |  | 
						
							| 53 | 1 2 22 23 25 33 45 36 47 | catcco |  | 
						
							| 54 | 53 | oveq1d |  | 
						
							| 55 | 41 | oveq2d |  | 
						
							| 56 | 52 54 55 | 3eqtr4d |  | 
						
							| 57 | 3 4 5 7 8 21 32 39 43 56 | iscatd2 |  |