| 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 5 6 7 8 9 10 | oppne1 |  |-  ( ph -> -. A e. D ) | 
						
							| 12 | 7 | ad3antrrr |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> G e. TarskiG ) | 
						
							| 13 | 8 | ad3antrrr |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> A e. P ) | 
						
							| 14 | 6 | ad3antrrr |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> D e. ran L ) | 
						
							| 15 |  | simplr |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> t e. D ) | 
						
							| 16 | 1 5 3 12 14 15 | tglnpt |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> t e. P ) | 
						
							| 17 |  | simpr |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> t e. ( A I B ) ) | 
						
							| 18 |  | simpllr |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> A = B ) | 
						
							| 19 | 18 | oveq2d |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> ( A I A ) = ( A I B ) ) | 
						
							| 20 | 17 19 | eleqtrrd |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> t e. ( A I A ) ) | 
						
							| 21 | 1 2 3 12 13 16 20 | axtgbtwnid |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> A = t ) | 
						
							| 22 | 21 15 | eqeltrd |  |-  ( ( ( ( ph /\ A = B ) /\ t e. D ) /\ t e. ( A I B ) ) -> A e. D ) | 
						
							| 23 | 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 ) ) ) ) | 
						
							| 24 | 10 23 | mpbid |  |-  ( ph -> ( ( -. A e. D /\ -. B e. D ) /\ E. t e. D t e. ( A I B ) ) ) | 
						
							| 25 | 24 | simprd |  |-  ( ph -> E. t e. D t e. ( A I B ) ) | 
						
							| 26 | 25 | adantr |  |-  ( ( ph /\ A = B ) -> E. t e. D t e. ( A I B ) ) | 
						
							| 27 | 22 26 | r19.29a |  |-  ( ( ph /\ A = B ) -> A e. D ) | 
						
							| 28 | 11 27 | mtand |  |-  ( ph -> -. A = B ) | 
						
							| 29 | 28 | neqned |  |-  ( ph -> A =/= B ) |