| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isprs.b |  | 
						
							| 2 |  | isprs.l |  | 
						
							| 3 |  | fveq2 |  | 
						
							| 4 |  | fveq2 |  | 
						
							| 5 | 4 | sbceq1d |  | 
						
							| 6 | 3 5 | sbceqbid |  | 
						
							| 7 |  | fvex |  | 
						
							| 8 |  | fvex |  | 
						
							| 9 |  | eqtr3 |  | 
						
							| 10 | 1 9 | mpan2 |  | 
						
							| 11 |  | raleq |  | 
						
							| 12 | 11 | raleqbi1dv |  | 
						
							| 13 | 12 | raleqbi1dv |  | 
						
							| 14 | 10 13 | syl |  | 
						
							| 15 |  | eqtr3 |  | 
						
							| 16 | 2 15 | mpan2 |  | 
						
							| 17 |  | breq |  | 
						
							| 18 |  | breq |  | 
						
							| 19 |  | breq |  | 
						
							| 20 | 18 19 | anbi12d |  | 
						
							| 21 |  | breq |  | 
						
							| 22 | 20 21 | imbi12d |  | 
						
							| 23 | 17 22 | anbi12d |  | 
						
							| 24 | 23 | ralbidv |  | 
						
							| 25 | 24 | 2ralbidv |  | 
						
							| 26 | 16 25 | syl |  | 
						
							| 27 | 14 26 | sylan9bb |  | 
						
							| 28 | 7 8 27 | sbc2ie |  | 
						
							| 29 | 6 28 | bitrdi |  | 
						
							| 30 |  | df-proset |  | 
						
							| 31 | 29 30 | elab4g |  |