| Step | Hyp | Ref | Expression | 
						
							| 1 |  | gasta.1 |  | 
						
							| 2 |  | gasta.2 |  | 
						
							| 3 |  | orbsta.r |  | 
						
							| 4 |  | orbsta.f |  | 
						
							| 5 |  | orbsta.o |  | 
						
							| 6 | 1 2 3 4 | orbstafun |  | 
						
							| 7 |  | simpr |  | 
						
							| 8 | 7 | adantr |  | 
						
							| 9 | 1 | gaf |  | 
						
							| 10 | 9 | adantr |  | 
						
							| 11 | 10 | adantr |  | 
						
							| 12 |  | simpr |  | 
						
							| 13 | 11 12 8 | fovcdmd |  | 
						
							| 14 |  | eqid |  | 
						
							| 15 |  | oveq1 |  | 
						
							| 16 | 15 | eqeq1d |  | 
						
							| 17 | 16 | rspcev |  | 
						
							| 18 | 12 14 17 | sylancl |  | 
						
							| 19 | 5 | gaorb |  | 
						
							| 20 | 8 13 18 19 | syl3anbrc |  | 
						
							| 21 |  | ovex |  | 
						
							| 22 |  | elecg |  | 
						
							| 23 | 21 8 22 | sylancr |  | 
						
							| 24 | 20 23 | mpbird |  | 
						
							| 25 | 1 2 | gastacl |  | 
						
							| 26 | 1 3 | eqger |  | 
						
							| 27 | 25 26 | syl |  | 
						
							| 28 | 1 | fvexi |  | 
						
							| 29 | 28 | a1i |  | 
						
							| 30 | 4 24 27 29 | qliftf |  | 
						
							| 31 | 6 30 | mpbid |  | 
						
							| 32 |  | eqid |  | 
						
							| 33 |  | fveqeq2 |  | 
						
							| 34 |  | eqeq1 |  | 
						
							| 35 | 33 34 | imbi12d |  | 
						
							| 36 | 35 | ralbidv |  | 
						
							| 37 |  | fveq2 |  | 
						
							| 38 | 37 | eqeq2d |  | 
						
							| 39 |  | eqeq2 |  | 
						
							| 40 | 38 39 | imbi12d |  | 
						
							| 41 | 1 2 3 4 | orbstaval |  | 
						
							| 42 | 41 | adantrr |  | 
						
							| 43 | 1 2 3 4 | orbstaval |  | 
						
							| 44 | 43 | adantrl |  | 
						
							| 45 | 42 44 | eqeq12d |  | 
						
							| 46 | 1 2 3 | gastacos |  | 
						
							| 47 | 27 | adantr |  | 
						
							| 48 |  | simprl |  | 
						
							| 49 | 47 48 | erth |  | 
						
							| 50 | 45 46 49 | 3bitr2d |  | 
						
							| 51 | 50 | biimpd |  | 
						
							| 52 | 51 | anassrs |  | 
						
							| 53 | 32 40 52 | ectocld |  | 
						
							| 54 | 53 | ralrimiva |  | 
						
							| 55 | 32 36 54 | ectocld |  | 
						
							| 56 | 55 | ralrimiva |  | 
						
							| 57 |  | dff13 |  | 
						
							| 58 | 31 56 57 | sylanbrc |  | 
						
							| 59 |  | vex |  | 
						
							| 60 |  | elecg |  | 
						
							| 61 | 59 7 60 | sylancr |  | 
						
							| 62 | 5 | gaorb |  | 
						
							| 63 | 61 62 | bitrdi |  | 
						
							| 64 | 63 | biimpa |  | 
						
							| 65 | 64 | simp3d |  | 
						
							| 66 | 3 | ovexi |  | 
						
							| 67 | 66 | ecelqsi |  | 
						
							| 68 | 43 | eqcomd |  | 
						
							| 69 |  | fveq2 |  | 
						
							| 70 | 69 | rspceeqv |  | 
						
							| 71 | 67 68 70 | syl2an2 |  | 
						
							| 72 |  | eqeq1 |  | 
						
							| 73 | 72 | rexbidv |  | 
						
							| 74 | 71 73 | syl5ibcom |  | 
						
							| 75 | 74 | rexlimdva |  | 
						
							| 76 | 75 | imp |  | 
						
							| 77 | 65 76 | syldan |  | 
						
							| 78 | 77 | ralrimiva |  | 
						
							| 79 |  | dffo3 |  | 
						
							| 80 | 31 78 79 | sylanbrc |  | 
						
							| 81 |  | df-f1o |  | 
						
							| 82 | 58 80 81 | sylanbrc |  |