| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dvdsadd2b |  |-  ( ( A e. ZZ /\ B e. ZZ /\ ( C e. ZZ /\ A || C ) ) -> ( A || B <-> A || ( C + B ) ) ) | 
						
							| 2 | 1 | a1d |  |-  ( ( A e. ZZ /\ B e. ZZ /\ ( C e. ZZ /\ A || C ) ) -> ( B e. RR -> ( A || B <-> A || ( C + B ) ) ) ) | 
						
							| 3 | 2 | 3exp |  |-  ( A e. ZZ -> ( B e. ZZ -> ( ( C e. ZZ /\ A || C ) -> ( B e. RR -> ( A || B <-> A || ( C + B ) ) ) ) ) ) | 
						
							| 4 | 3 | com24 |  |-  ( A e. ZZ -> ( B e. RR -> ( ( C e. ZZ /\ A || C ) -> ( B e. ZZ -> ( A || B <-> A || ( C + B ) ) ) ) ) ) | 
						
							| 5 | 4 | 3imp |  |-  ( ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) -> ( B e. ZZ -> ( A || B <-> A || ( C + B ) ) ) ) | 
						
							| 6 | 5 | com12 |  |-  ( B e. ZZ -> ( ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) -> ( A || B <-> A || ( C + B ) ) ) ) | 
						
							| 7 |  | dvdszrcl |  |-  ( A || B -> ( A e. ZZ /\ B e. ZZ ) ) | 
						
							| 8 |  | pm2.24 |  |-  ( B e. ZZ -> ( -. B e. ZZ -> A || ( C + B ) ) ) | 
						
							| 9 | 7 8 | simpl2im |  |-  ( A || B -> ( -. B e. ZZ -> A || ( C + B ) ) ) | 
						
							| 10 | 9 | com12 |  |-  ( -. B e. ZZ -> ( A || B -> A || ( C + B ) ) ) | 
						
							| 11 | 10 | adantr |  |-  ( ( -. B e. ZZ /\ ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) ) -> ( A || B -> A || ( C + B ) ) ) | 
						
							| 12 |  | dvdszrcl |  |-  ( A || ( C + B ) -> ( A e. ZZ /\ ( C + B ) e. ZZ ) ) | 
						
							| 13 |  | zcn |  |-  ( C e. ZZ -> C e. CC ) | 
						
							| 14 | 13 | adantr |  |-  ( ( C e. ZZ /\ ( B e. RR /\ -. B e. ZZ ) ) -> C e. CC ) | 
						
							| 15 |  | recn |  |-  ( B e. RR -> B e. CC ) | 
						
							| 16 | 15 | ad2antrl |  |-  ( ( C e. ZZ /\ ( B e. RR /\ -. B e. ZZ ) ) -> B e. CC ) | 
						
							| 17 | 14 16 | addcomd |  |-  ( ( C e. ZZ /\ ( B e. RR /\ -. B e. ZZ ) ) -> ( C + B ) = ( B + C ) ) | 
						
							| 18 |  | eldif |  |-  ( B e. ( RR \ ZZ ) <-> ( B e. RR /\ -. B e. ZZ ) ) | 
						
							| 19 |  | nzadd |  |-  ( ( B e. ( RR \ ZZ ) /\ C e. ZZ ) -> ( B + C ) e. ( RR \ ZZ ) ) | 
						
							| 20 | 19 | eldifbd |  |-  ( ( B e. ( RR \ ZZ ) /\ C e. ZZ ) -> -. ( B + C ) e. ZZ ) | 
						
							| 21 | 20 | expcom |  |-  ( C e. ZZ -> ( B e. ( RR \ ZZ ) -> -. ( B + C ) e. ZZ ) ) | 
						
							| 22 | 18 21 | biimtrrid |  |-  ( C e. ZZ -> ( ( B e. RR /\ -. B e. ZZ ) -> -. ( B + C ) e. ZZ ) ) | 
						
							| 23 | 22 | imp |  |-  ( ( C e. ZZ /\ ( B e. RR /\ -. B e. ZZ ) ) -> -. ( B + C ) e. ZZ ) | 
						
							| 24 | 17 23 | eqneltrd |  |-  ( ( C e. ZZ /\ ( B e. RR /\ -. B e. ZZ ) ) -> -. ( C + B ) e. ZZ ) | 
						
							| 25 | 24 | exp32 |  |-  ( C e. ZZ -> ( B e. RR -> ( -. B e. ZZ -> -. ( C + B ) e. ZZ ) ) ) | 
						
							| 26 |  | pm2.21 |  |-  ( -. ( C + B ) e. ZZ -> ( ( C + B ) e. ZZ -> A || B ) ) | 
						
							| 27 | 25 26 | syl8 |  |-  ( C e. ZZ -> ( B e. RR -> ( -. B e. ZZ -> ( ( C + B ) e. ZZ -> A || B ) ) ) ) | 
						
							| 28 | 27 | adantr |  |-  ( ( C e. ZZ /\ A || C ) -> ( B e. RR -> ( -. B e. ZZ -> ( ( C + B ) e. ZZ -> A || B ) ) ) ) | 
						
							| 29 | 28 | com12 |  |-  ( B e. RR -> ( ( C e. ZZ /\ A || C ) -> ( -. B e. ZZ -> ( ( C + B ) e. ZZ -> A || B ) ) ) ) | 
						
							| 30 | 29 | a1i |  |-  ( A e. ZZ -> ( B e. RR -> ( ( C e. ZZ /\ A || C ) -> ( -. B e. ZZ -> ( ( C + B ) e. ZZ -> A || B ) ) ) ) ) | 
						
							| 31 | 30 | 3imp |  |-  ( ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) -> ( -. B e. ZZ -> ( ( C + B ) e. ZZ -> A || B ) ) ) | 
						
							| 32 | 31 | impcom |  |-  ( ( -. B e. ZZ /\ ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) ) -> ( ( C + B ) e. ZZ -> A || B ) ) | 
						
							| 33 | 32 | com12 |  |-  ( ( C + B ) e. ZZ -> ( ( -. B e. ZZ /\ ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) ) -> A || B ) ) | 
						
							| 34 | 12 33 | simpl2im |  |-  ( A || ( C + B ) -> ( ( -. B e. ZZ /\ ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) ) -> A || B ) ) | 
						
							| 35 | 34 | com12 |  |-  ( ( -. B e. ZZ /\ ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) ) -> ( A || ( C + B ) -> A || B ) ) | 
						
							| 36 | 11 35 | impbid |  |-  ( ( -. B e. ZZ /\ ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) ) -> ( A || B <-> A || ( C + B ) ) ) | 
						
							| 37 | 36 | ex |  |-  ( -. B e. ZZ -> ( ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) -> ( A || B <-> A || ( C + B ) ) ) ) | 
						
							| 38 | 6 37 | pm2.61i |  |-  ( ( A e. ZZ /\ B e. RR /\ ( C e. ZZ /\ A || C ) ) -> ( A || B <-> A || ( C + B ) ) ) |