| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpl |  |-  ( ( N e. ( ZZ>= ` A ) /\ B < A ) -> N e. ( ZZ>= ` A ) ) | 
						
							| 2 | 1 | adantl |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> N e. ( ZZ>= ` A ) ) | 
						
							| 3 |  | simpl |  |-  ( ( A e. ZZ /\ B e. ZZ ) -> A e. ZZ ) | 
						
							| 4 | 3 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> A e. ZZ ) | 
						
							| 5 |  | eluzelz |  |-  ( N e. ( ZZ>= ` A ) -> N e. ZZ ) | 
						
							| 6 | 5 | ad2antrr |  |-  ( ( ( N e. ( ZZ>= ` A ) /\ B < A ) /\ ( A e. ZZ /\ B e. ZZ ) ) -> N e. ZZ ) | 
						
							| 7 |  | simprr |  |-  ( ( ( N e. ( ZZ>= ` A ) /\ B < A ) /\ ( A e. ZZ /\ B e. ZZ ) ) -> B e. ZZ ) | 
						
							| 8 | 6 7 | zsubcld |  |-  ( ( ( N e. ( ZZ>= ` A ) /\ B < A ) /\ ( A e. ZZ /\ B e. ZZ ) ) -> ( N - B ) e. ZZ ) | 
						
							| 9 | 8 | ancoms |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> ( N - B ) e. ZZ ) | 
						
							| 10 | 4 9 | zaddcld |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> ( A + ( N - B ) ) e. ZZ ) | 
						
							| 11 |  | zre |  |-  ( B e. ZZ -> B e. RR ) | 
						
							| 12 |  | zre |  |-  ( A e. ZZ -> A e. RR ) | 
						
							| 13 |  | posdif |  |-  ( ( B e. RR /\ A e. RR ) -> ( B < A <-> 0 < ( A - B ) ) ) | 
						
							| 14 | 13 | biimpd |  |-  ( ( B e. RR /\ A e. RR ) -> ( B < A -> 0 < ( A - B ) ) ) | 
						
							| 15 | 11 12 14 | syl2anr |  |-  ( ( A e. ZZ /\ B e. ZZ ) -> ( B < A -> 0 < ( A - B ) ) ) | 
						
							| 16 | 15 | adantld |  |-  ( ( A e. ZZ /\ B e. ZZ ) -> ( ( N e. ( ZZ>= ` A ) /\ B < A ) -> 0 < ( A - B ) ) ) | 
						
							| 17 | 16 | imp |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> 0 < ( A - B ) ) | 
						
							| 18 |  | resubcl |  |-  ( ( A e. RR /\ B e. RR ) -> ( A - B ) e. RR ) | 
						
							| 19 | 12 11 18 | syl2an |  |-  ( ( A e. ZZ /\ B e. ZZ ) -> ( A - B ) e. RR ) | 
						
							| 20 | 19 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> ( A - B ) e. RR ) | 
						
							| 21 |  | eluzelre |  |-  ( N e. ( ZZ>= ` A ) -> N e. RR ) | 
						
							| 22 | 21 | ad2antrl |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> N e. RR ) | 
						
							| 23 | 20 22 | ltaddposd |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> ( 0 < ( A - B ) <-> N < ( N + ( A - B ) ) ) ) | 
						
							| 24 | 17 23 | mpbid |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> N < ( N + ( A - B ) ) ) | 
						
							| 25 |  | zcn |  |-  ( A e. ZZ -> A e. CC ) | 
						
							| 26 | 25 | ad2antrr |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> A e. CC ) | 
						
							| 27 |  | eluzelcn |  |-  ( N e. ( ZZ>= ` A ) -> N e. CC ) | 
						
							| 28 | 27 | ad2antrl |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> N e. CC ) | 
						
							| 29 |  | zcn |  |-  ( B e. ZZ -> B e. CC ) | 
						
							| 30 | 29 | adantl |  |-  ( ( A e. ZZ /\ B e. ZZ ) -> B e. CC ) | 
						
							| 31 | 30 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> B e. CC ) | 
						
							| 32 |  | addsub12 |  |-  ( ( A e. CC /\ N e. CC /\ B e. CC ) -> ( A + ( N - B ) ) = ( N + ( A - B ) ) ) | 
						
							| 33 | 32 | breq2d |  |-  ( ( A e. CC /\ N e. CC /\ B e. CC ) -> ( N < ( A + ( N - B ) ) <-> N < ( N + ( A - B ) ) ) ) | 
						
							| 34 | 26 28 31 33 | syl3anc |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> ( N < ( A + ( N - B ) ) <-> N < ( N + ( A - B ) ) ) ) | 
						
							| 35 | 24 34 | mpbird |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> N < ( A + ( N - B ) ) ) | 
						
							| 36 |  | elfzo2 |  |-  ( N e. ( A ..^ ( A + ( N - B ) ) ) <-> ( N e. ( ZZ>= ` A ) /\ ( A + ( N - B ) ) e. ZZ /\ N < ( A + ( N - B ) ) ) ) | 
						
							| 37 | 2 10 35 36 | syl3anbrc |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> N e. ( A ..^ ( A + ( N - B ) ) ) ) | 
						
							| 38 |  | fzosubel3 |  |-  ( ( N e. ( A ..^ ( A + ( N - B ) ) ) /\ ( N - B ) e. ZZ ) -> ( N - A ) e. ( 0 ..^ ( N - B ) ) ) | 
						
							| 39 | 37 9 38 | syl2anc |  |-  ( ( ( A e. ZZ /\ B e. ZZ ) /\ ( N e. ( ZZ>= ` A ) /\ B < A ) ) -> ( N - A ) e. ( 0 ..^ ( N - B ) ) ) | 
						
							| 40 | 39 | ex |  |-  ( ( A e. ZZ /\ B e. ZZ ) -> ( ( N e. ( ZZ>= ` A ) /\ B < A ) -> ( N - A ) e. ( 0 ..^ ( N - B ) ) ) ) |