| Step | Hyp | Ref | Expression | 
						
							| 1 |  | spansncv.1 |  | 
						
							| 2 |  | spansncv.2 |  | 
						
							| 3 |  | spansncv.3 |  | 
						
							| 4 |  | simpr |  | 
						
							| 5 |  | pssss |  | 
						
							| 6 | 5 | adantr |  | 
						
							| 7 |  | pssnel |  | 
						
							| 8 |  | ssel2 |  | 
						
							| 9 | 1 3 | spansnji |  | 
						
							| 10 | 9 | eleq2i |  | 
						
							| 11 | 3 | spansnchi |  | 
						
							| 12 | 1 11 | chseli |  | 
						
							| 13 | 10 12 | bitr3i |  | 
						
							| 14 |  | eleq1 |  | 
						
							| 15 | 14 | biimpac |  | 
						
							| 16 | 5 | sselda |  | 
						
							| 17 | 2 | chshii |  | 
						
							| 18 |  | shsubcl |  | 
						
							| 19 | 17 18 | mp3an1 |  | 
						
							| 20 | 15 16 19 | syl2an |  | 
						
							| 21 | 20 | exp43 |  | 
						
							| 22 | 21 | com14 |  | 
						
							| 23 | 22 | imp45 |  | 
						
							| 24 | 1 | cheli |  | 
						
							| 25 | 11 | cheli |  | 
						
							| 26 |  | hvpncan2 |  | 
						
							| 27 | 24 25 26 | syl2an |  | 
						
							| 28 | 27 | eleq1d |  | 
						
							| 29 | 23 28 | imbitrid |  | 
						
							| 30 | 29 | imp |  | 
						
							| 31 | 30 | anandis |  | 
						
							| 32 | 31 | exp45 |  | 
						
							| 33 | 32 | imp41 |  | 
						
							| 34 | 33 | adantrr |  | 
						
							| 35 |  | oveq2 |  | 
						
							| 36 |  | ax-hvaddid |  | 
						
							| 37 | 24 36 | syl |  | 
						
							| 38 | 35 37 | sylan9eqr |  | 
						
							| 39 | 38 | eqeq2d |  | 
						
							| 40 |  | eleq1a |  | 
						
							| 41 | 40 | adantr |  | 
						
							| 42 | 39 41 | sylbid |  | 
						
							| 43 | 42 | impancom |  | 
						
							| 44 | 43 | necon3bd |  | 
						
							| 45 | 44 | imp |  | 
						
							| 46 |  | spansnss |  | 
						
							| 47 | 17 46 | mpan |  | 
						
							| 48 |  | spansneleq |  | 
						
							| 49 | 3 48 | mpan |  | 
						
							| 50 | 49 | imp |  | 
						
							| 51 | 50 | sseq1d |  | 
						
							| 52 | 47 51 | imbitrid |  | 
						
							| 53 | 52 | ancoms |  | 
						
							| 54 | 45 53 | sylan2 |  | 
						
							| 55 | 54 | exp44 |  | 
						
							| 56 | 55 | com12 |  | 
						
							| 57 | 56 | imp41 |  | 
						
							| 58 | 57 | adantrl |  | 
						
							| 59 | 34 58 | mpd |  | 
						
							| 60 | 59 | exp43 |  | 
						
							| 61 | 60 | rexlimivv |  | 
						
							| 62 | 13 61 | sylbi |  | 
						
							| 63 | 8 62 | syl |  | 
						
							| 64 | 63 | imp |  | 
						
							| 65 | 64 | anandirs |  | 
						
							| 66 | 65 | expimpd |  | 
						
							| 67 | 66 | exlimdv |  | 
						
							| 68 | 7 67 | syl5 |  | 
						
							| 69 | 68 | ex |  | 
						
							| 70 | 69 | pm2.43d |  | 
						
							| 71 | 70 | impcom |  | 
						
							| 72 | 1 11 2 | chlubii |  | 
						
							| 73 | 6 71 72 | syl2anc |  | 
						
							| 74 | 4 73 | eqssd |  |