| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dochval.b |  | 
						
							| 2 |  | dochval.g |  | 
						
							| 3 |  | dochval.o |  | 
						
							| 4 |  | dochval.h |  | 
						
							| 5 |  | elex |  | 
						
							| 6 |  | fveq2 |  | 
						
							| 7 | 6 4 | eqtr4di |  | 
						
							| 8 |  | fveq2 |  | 
						
							| 9 | 8 | fveq1d |  | 
						
							| 10 | 9 | fveq2d |  | 
						
							| 11 | 10 | pweqd |  | 
						
							| 12 |  | fveq2 |  | 
						
							| 13 | 12 | fveq1d |  | 
						
							| 14 |  | fveq2 |  | 
						
							| 15 | 14 3 | eqtr4di |  | 
						
							| 16 |  | fveq2 |  | 
						
							| 17 | 16 2 | eqtr4di |  | 
						
							| 18 |  | fveq2 |  | 
						
							| 19 | 18 1 | eqtr4di |  | 
						
							| 20 | 13 | fveq1d |  | 
						
							| 21 | 20 | sseq2d |  | 
						
							| 22 | 19 21 | rabeqbidv |  | 
						
							| 23 | 17 22 | fveq12d |  | 
						
							| 24 | 15 23 | fveq12d |  | 
						
							| 25 | 13 24 | fveq12d |  | 
						
							| 26 | 11 25 | mpteq12dv |  | 
						
							| 27 | 7 26 | mpteq12dv |  | 
						
							| 28 |  | df-doch |  | 
						
							| 29 | 27 28 4 | mptfvmpt |  | 
						
							| 30 | 5 29 | syl |  |