| Step | Hyp | Ref | Expression | 
						
							| 1 |  | hpg.p |  |-  P = ( Base ` G ) | 
						
							| 2 |  | hpg.d |  |-  .- = ( dist ` G ) | 
						
							| 3 |  | hpg.i |  |-  I = ( Itv ` G ) | 
						
							| 4 |  | hpg.o |  |-  O = { <. a , b >. | ( ( a e. ( P \ D ) /\ b e. ( P \ D ) ) /\ E. t e. D t e. ( a I b ) ) } | 
						
							| 5 |  | opphl.l |  |-  L = ( LineG ` G ) | 
						
							| 6 |  | opphl.d |  |-  ( ph -> D e. ran L ) | 
						
							| 7 |  | opphl.g |  |-  ( ph -> G e. TarskiG ) | 
						
							| 8 |  | oppcom.a |  |-  ( ph -> A e. P ) | 
						
							| 9 |  | oppcom.b |  |-  ( ph -> B e. P ) | 
						
							| 10 |  | oppcom.o |  |-  ( ph -> A O B ) | 
						
							| 11 | 1 2 3 4 8 9 | islnopp |  |-  ( ph -> ( A O B <-> ( ( -. A e. D /\ -. B e. D ) /\ E. t e. D t e. ( A I B ) ) ) ) | 
						
							| 12 | 10 11 | mpbid |  |-  ( ph -> ( ( -. A e. D /\ -. B e. D ) /\ E. t e. D t e. ( A I B ) ) ) | 
						
							| 13 | 12 | simpld |  |-  ( ph -> ( -. A e. D /\ -. B e. D ) ) | 
						
							| 14 | 13 | simprd |  |-  ( ph -> -. B e. D ) | 
						
							| 15 | 13 | simpld |  |-  ( ph -> -. A e. D ) | 
						
							| 16 | 12 | simprd |  |-  ( ph -> E. t e. D t e. ( A I B ) ) | 
						
							| 17 | 7 | ad2antrr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( A I B ) ) -> G e. TarskiG ) | 
						
							| 18 | 8 | ad2antrr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( A I B ) ) -> A e. P ) | 
						
							| 19 | 7 | adantr |  |-  ( ( ph /\ t e. D ) -> G e. TarskiG ) | 
						
							| 20 | 6 | adantr |  |-  ( ( ph /\ t e. D ) -> D e. ran L ) | 
						
							| 21 |  | simpr |  |-  ( ( ph /\ t e. D ) -> t e. D ) | 
						
							| 22 | 1 5 3 19 20 21 | tglnpt |  |-  ( ( ph /\ t e. D ) -> t e. P ) | 
						
							| 23 | 22 | adantr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( A I B ) ) -> t e. P ) | 
						
							| 24 | 9 | ad2antrr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( A I B ) ) -> B e. P ) | 
						
							| 25 |  | simpr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( A I B ) ) -> t e. ( A I B ) ) | 
						
							| 26 | 1 2 3 17 18 23 24 25 | tgbtwncom |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( A I B ) ) -> t e. ( B I A ) ) | 
						
							| 27 | 7 | ad2antrr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( B I A ) ) -> G e. TarskiG ) | 
						
							| 28 | 9 | ad2antrr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( B I A ) ) -> B e. P ) | 
						
							| 29 | 22 | adantr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( B I A ) ) -> t e. P ) | 
						
							| 30 | 8 | ad2antrr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( B I A ) ) -> A e. P ) | 
						
							| 31 |  | simpr |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( B I A ) ) -> t e. ( B I A ) ) | 
						
							| 32 | 1 2 3 27 28 29 30 31 | tgbtwncom |  |-  ( ( ( ph /\ t e. D ) /\ t e. ( B I A ) ) -> t e. ( A I B ) ) | 
						
							| 33 | 26 32 | impbida |  |-  ( ( ph /\ t e. D ) -> ( t e. ( A I B ) <-> t e. ( B I A ) ) ) | 
						
							| 34 | 33 | rexbidva |  |-  ( ph -> ( E. t e. D t e. ( A I B ) <-> E. t e. D t e. ( B I A ) ) ) | 
						
							| 35 | 16 34 | mpbid |  |-  ( ph -> E. t e. D t e. ( B I A ) ) | 
						
							| 36 | 14 15 35 | jca31 |  |-  ( ph -> ( ( -. B e. D /\ -. A e. D ) /\ E. t e. D t e. ( B I A ) ) ) | 
						
							| 37 | 1 2 3 4 9 8 | islnopp |  |-  ( ph -> ( B O A <-> ( ( -. B e. D /\ -. A e. D ) /\ E. t e. D t e. ( B I A ) ) ) ) | 
						
							| 38 | 36 37 | mpbird |  |-  ( ph -> B O A ) |