| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cvrfval.b |  | 
						
							| 2 |  | cvrfval.s |  | 
						
							| 3 |  | cvrfval.c |  | 
						
							| 4 |  | elex |  | 
						
							| 5 |  | fveq2 |  | 
						
							| 6 | 5 1 | eqtr4di |  | 
						
							| 7 | 6 | eleq2d |  | 
						
							| 8 | 6 | eleq2d |  | 
						
							| 9 | 7 8 | anbi12d |  | 
						
							| 10 |  | fveq2 |  | 
						
							| 11 | 10 2 | eqtr4di |  | 
						
							| 12 | 11 | breqd |  | 
						
							| 13 | 11 | breqd |  | 
						
							| 14 | 11 | breqd |  | 
						
							| 15 | 13 14 | anbi12d |  | 
						
							| 16 | 6 15 | rexeqbidv |  | 
						
							| 17 | 16 | notbid |  | 
						
							| 18 | 9 12 17 | 3anbi123d |  | 
						
							| 19 | 18 | opabbidv |  | 
						
							| 20 |  | df-covers |  | 
						
							| 21 |  | 3anass |  | 
						
							| 22 | 21 | opabbii |  | 
						
							| 23 | 1 | fvexi |  | 
						
							| 24 | 23 23 | xpex |  | 
						
							| 25 |  | opabssxp |  | 
						
							| 26 | 24 25 | ssexi |  | 
						
							| 27 | 22 26 | eqeltri |  | 
						
							| 28 | 19 20 27 | fvmpt |  | 
						
							| 29 | 3 28 | eqtrid |  | 
						
							| 30 | 4 29 | syl |  |