| Step | Hyp | Ref | Expression | 
						
							| 1 |  | brecop.1 |  | 
						
							| 2 |  | brecop.2 |  | 
						
							| 3 |  | brecop.4 |  | 
						
							| 4 |  | brecop.5 |  | 
						
							| 5 |  | brecop.6 |  | 
						
							| 6 | 1 3 | ecopqsi |  | 
						
							| 7 | 1 3 | ecopqsi |  | 
						
							| 8 |  | df-br |  | 
						
							| 9 | 4 | eleq2i |  | 
						
							| 10 | 8 9 | bitri |  | 
						
							| 11 |  | eqeq1 |  | 
						
							| 12 | 11 | anbi1d |  | 
						
							| 13 | 12 | anbi1d |  | 
						
							| 14 | 13 | 4exbidv |  | 
						
							| 15 |  | eqeq1 |  | 
						
							| 16 | 15 | anbi2d |  | 
						
							| 17 | 16 | anbi1d |  | 
						
							| 18 | 17 | 4exbidv |  | 
						
							| 19 | 14 18 | opelopab2 |  | 
						
							| 20 | 10 19 | bitrid |  | 
						
							| 21 | 6 7 20 | syl2an |  | 
						
							| 22 |  | opeq12 |  | 
						
							| 23 | 22 | eceq1d |  | 
						
							| 24 |  | opeq12 |  | 
						
							| 25 | 24 | eceq1d |  | 
						
							| 26 | 23 25 | anim12i |  | 
						
							| 27 |  | opelxpi |  | 
						
							| 28 |  | opelxp |  | 
						
							| 29 | 2 | a1i |  | 
						
							| 30 |  | id |  | 
						
							| 31 | 29 30 | ereldm |  | 
						
							| 32 | 28 31 | bitr3id |  | 
						
							| 33 | 27 32 | imbitrrid |  | 
						
							| 34 |  | opelxpi |  | 
						
							| 35 |  | opelxp |  | 
						
							| 36 | 2 | a1i |  | 
						
							| 37 |  | id |  | 
						
							| 38 | 36 37 | ereldm |  | 
						
							| 39 | 35 38 | bitr3id |  | 
						
							| 40 | 34 39 | imbitrrid |  | 
						
							| 41 | 33 40 | im2anan9 |  | 
						
							| 42 | 5 | an4s |  | 
						
							| 43 | 42 | ex |  | 
						
							| 44 | 43 | com13 |  | 
						
							| 45 | 41 44 | mpdd |  | 
						
							| 46 | 45 | pm5.74d |  | 
						
							| 47 | 26 46 | cgsex4g |  | 
						
							| 48 |  | eqcom |  | 
						
							| 49 |  | eqcom |  | 
						
							| 50 | 48 49 | anbi12i |  | 
						
							| 51 | 50 | a1i |  | 
						
							| 52 |  | biimt |  | 
						
							| 53 | 51 52 | anbi12d |  | 
						
							| 54 | 53 | 4exbidv |  | 
						
							| 55 |  | biimt |  | 
						
							| 56 | 47 54 55 | 3bitr4d |  | 
						
							| 57 | 21 56 | bitrd |  |