| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ecgrtg.1 |  | 
						
							| 2 |  | ecgrtg.2 |  | 
						
							| 3 |  | ecgrtg.3 |  | 
						
							| 4 |  | ecgrtg.a |  | 
						
							| 5 |  | ecgrtg.b |  | 
						
							| 6 |  | ecgrtg.c |  | 
						
							| 7 |  | ecgrtg.d |  | 
						
							| 8 |  | eengbas |  | 
						
							| 9 | 1 8 | syl |  | 
						
							| 10 | 9 2 | eqtr4di |  | 
						
							| 11 | 4 10 | eleqtrrd |  | 
						
							| 12 | 5 10 | eleqtrrd |  | 
						
							| 13 | 6 10 | eleqtrrd |  | 
						
							| 14 | 7 10 | eleqtrrd |  | 
						
							| 15 |  | brcgr |  | 
						
							| 16 | 11 12 13 14 15 | syl22anc |  | 
						
							| 17 |  | dsid |  | 
						
							| 18 |  | fvexd |  | 
						
							| 19 |  | eengstr |  | 
						
							| 20 | 1 19 | syl |  | 
						
							| 21 |  | structn0fun |  | 
						
							| 22 | 20 21 | syl |  | 
						
							| 23 |  | structcnvcnv |  | 
						
							| 24 | 20 23 | syl |  | 
						
							| 25 | 24 | funeqd |  | 
						
							| 26 | 22 25 | mpbird |  | 
						
							| 27 |  | opex |  | 
						
							| 28 | 27 | prid2 |  | 
						
							| 29 |  | elun1 |  | 
						
							| 30 | 28 29 | ax-mp |  | 
						
							| 31 |  | eengv |  | 
						
							| 32 | 1 31 | syl |  | 
						
							| 33 | 30 32 | eleqtrrid |  | 
						
							| 34 |  | fvex |  | 
						
							| 35 | 34 34 | mpoex |  | 
						
							| 36 | 35 | a1i |  | 
						
							| 37 | 17 18 26 33 36 | strfv2d |  | 
						
							| 38 | 3 37 | eqtr4id |  | 
						
							| 39 |  | simplrl |  | 
						
							| 40 | 39 | fveq1d |  | 
						
							| 41 |  | simplrr |  | 
						
							| 42 | 41 | fveq1d |  | 
						
							| 43 | 40 42 | oveq12d |  | 
						
							| 44 | 43 | oveq1d |  | 
						
							| 45 | 44 | sumeq2dv |  | 
						
							| 46 |  | sumex |  | 
						
							| 47 | 46 | a1i |  | 
						
							| 48 | 38 45 11 12 47 | ovmpod |  | 
						
							| 49 | 48 | eqcomd |  | 
						
							| 50 |  | simplrl |  | 
						
							| 51 | 50 | fveq1d |  | 
						
							| 52 |  | simplrr |  | 
						
							| 53 | 52 | fveq1d |  | 
						
							| 54 | 51 53 | oveq12d |  | 
						
							| 55 | 54 | oveq1d |  | 
						
							| 56 | 55 | sumeq2dv |  | 
						
							| 57 |  | sumex |  | 
						
							| 58 | 57 | a1i |  | 
						
							| 59 | 38 56 13 14 58 | ovmpod |  | 
						
							| 60 | 59 | eqcomd |  | 
						
							| 61 | 49 60 | eqeq12d |  | 
						
							| 62 | 16 61 | bitrd |  |