| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eluzelz |  |-  ( B e. ( ZZ>= ` A ) -> B e. ZZ ) | 
						
							| 2 | 1 | ad2antrr |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> B e. ZZ ) | 
						
							| 3 | 2 | zred |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> B e. RR ) | 
						
							| 4 |  | eluzel2 |  |-  ( B e. ( ZZ>= ` A ) -> A e. ZZ ) | 
						
							| 5 | 4 | ad2antrr |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> A e. ZZ ) | 
						
							| 6 | 5 | zred |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> A e. RR ) | 
						
							| 7 | 3 6 | resubcld |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( B - A ) e. RR ) | 
						
							| 8 |  | simplr |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> C e. ZZ ) | 
						
							| 9 | 8 | zred |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> C e. RR ) | 
						
							| 10 | 9 6 | resubcld |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( C - A ) e. RR ) | 
						
							| 11 |  | 1red |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> 1 e. RR ) | 
						
							| 12 |  | simpr |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> B < C ) | 
						
							| 13 | 3 9 6 12 | ltsub1dd |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( B - A ) < ( C - A ) ) | 
						
							| 14 | 7 10 11 13 | ltadd1dd |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( ( B - A ) + 1 ) < ( ( C - A ) + 1 ) ) | 
						
							| 15 |  | hashfz |  |-  ( B e. ( ZZ>= ` A ) -> ( # ` ( A ... B ) ) = ( ( B - A ) + 1 ) ) | 
						
							| 16 | 15 | ad2antrr |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( # ` ( A ... B ) ) = ( ( B - A ) + 1 ) ) | 
						
							| 17 | 3 9 12 | ltled |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> B <_ C ) | 
						
							| 18 |  | eluz2 |  |-  ( C e. ( ZZ>= ` B ) <-> ( B e. ZZ /\ C e. ZZ /\ B <_ C ) ) | 
						
							| 19 | 2 8 17 18 | syl3anbrc |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> C e. ( ZZ>= ` B ) ) | 
						
							| 20 |  | simpll |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> B e. ( ZZ>= ` A ) ) | 
						
							| 21 |  | uztrn |  |-  ( ( C e. ( ZZ>= ` B ) /\ B e. ( ZZ>= ` A ) ) -> C e. ( ZZ>= ` A ) ) | 
						
							| 22 | 19 20 21 | syl2anc |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> C e. ( ZZ>= ` A ) ) | 
						
							| 23 |  | hashfz |  |-  ( C e. ( ZZ>= ` A ) -> ( # ` ( A ... C ) ) = ( ( C - A ) + 1 ) ) | 
						
							| 24 | 22 23 | syl |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( # ` ( A ... C ) ) = ( ( C - A ) + 1 ) ) | 
						
							| 25 | 14 16 24 | 3brtr4d |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( # ` ( A ... B ) ) < ( # ` ( A ... C ) ) ) | 
						
							| 26 |  | fzfi |  |-  ( A ... B ) e. Fin | 
						
							| 27 |  | fzfi |  |-  ( A ... C ) e. Fin | 
						
							| 28 |  | hashsdom |  |-  ( ( ( A ... B ) e. Fin /\ ( A ... C ) e. Fin ) -> ( ( # ` ( A ... B ) ) < ( # ` ( A ... C ) ) <-> ( A ... B ) ~< ( A ... C ) ) ) | 
						
							| 29 | 26 27 28 | mp2an |  |-  ( ( # ` ( A ... B ) ) < ( # ` ( A ... C ) ) <-> ( A ... B ) ~< ( A ... C ) ) | 
						
							| 30 | 25 29 | sylib |  |-  ( ( ( B e. ( ZZ>= ` A ) /\ C e. ZZ ) /\ B < C ) -> ( A ... B ) ~< ( A ... C ) ) |