| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cgrextendand.1 |  |-  ( ph -> N e. NN ) | 
						
							| 2 |  | cgrextendand.2 |  |-  ( ph -> A e. ( EE ` N ) ) | 
						
							| 3 |  | cgrextendand.3 |  |-  ( ph -> B e. ( EE ` N ) ) | 
						
							| 4 |  | cgrextendand.4 |  |-  ( ph -> C e. ( EE ` N ) ) | 
						
							| 5 |  | cgrextendand.5 |  |-  ( ph -> D e. ( EE ` N ) ) | 
						
							| 6 |  | cgrextendand.6 |  |-  ( ph -> E e. ( EE ` N ) ) | 
						
							| 7 |  | cgrextendand.7 |  |-  ( ph -> F e. ( EE ` N ) ) | 
						
							| 8 |  | cgrextendand.8 |  |-  ( ( ph /\ ps ) -> B Btwn <. A , C >. ) | 
						
							| 9 |  | cgrextendand.9 |  |-  ( ( ph /\ ps ) -> E Btwn <. D , F >. ) | 
						
							| 10 |  | cgrextendand.10 |  |-  ( ( ph /\ ps ) -> <. A , B >. Cgr <. D , E >. ) | 
						
							| 11 |  | cgrextendand.11 |  |-  ( ( ph /\ ps ) -> <. B , C >. Cgr <. E , F >. ) | 
						
							| 12 | 8 9 | jca |  |-  ( ( ph /\ ps ) -> ( B Btwn <. A , C >. /\ E Btwn <. D , F >. ) ) | 
						
							| 13 | 10 11 | jca |  |-  ( ( ph /\ ps ) -> ( <. A , B >. Cgr <. D , E >. /\ <. B , C >. Cgr <. E , F >. ) ) | 
						
							| 14 |  | cgrextend |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) /\ ( D e. ( EE ` N ) /\ E e. ( EE ` N ) /\ F e. ( EE ` N ) ) ) -> ( ( ( B Btwn <. A , C >. /\ E Btwn <. D , F >. ) /\ ( <. A , B >. Cgr <. D , E >. /\ <. B , C >. Cgr <. E , F >. ) ) -> <. A , C >. Cgr <. D , F >. ) ) | 
						
							| 15 | 1 2 3 4 5 6 7 14 | syl133anc |  |-  ( ph -> ( ( ( B Btwn <. A , C >. /\ E Btwn <. D , F >. ) /\ ( <. A , B >. Cgr <. D , E >. /\ <. B , C >. Cgr <. E , F >. ) ) -> <. A , C >. Cgr <. D , F >. ) ) | 
						
							| 16 | 15 | adantr |  |-  ( ( ph /\ ps ) -> ( ( ( B Btwn <. A , C >. /\ E Btwn <. D , F >. ) /\ ( <. A , B >. Cgr <. D , E >. /\ <. B , C >. Cgr <. E , F >. ) ) -> <. A , C >. Cgr <. D , F >. ) ) | 
						
							| 17 | 12 13 16 | mp2and |  |-  ( ( ph /\ ps ) -> <. A , C >. Cgr <. D , F >. ) |