| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 2re |  |-  2 e. RR | 
						
							| 2 |  | simp1 |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> A e. RR ) | 
						
							| 3 |  | remulcl |  |-  ( ( 2 e. RR /\ A e. RR ) -> ( 2 x. A ) e. RR ) | 
						
							| 4 | 1 2 3 | sylancr |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> ( 2 x. A ) e. RR ) | 
						
							| 5 |  | simp3 |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> 1 < B ) | 
						
							| 6 |  | 1re |  |-  1 e. RR | 
						
							| 7 |  | simp2 |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> B e. RR ) | 
						
							| 8 |  | difrp |  |-  ( ( 1 e. RR /\ B e. RR ) -> ( 1 < B <-> ( B - 1 ) e. RR+ ) ) | 
						
							| 9 | 6 7 8 | sylancr |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> ( 1 < B <-> ( B - 1 ) e. RR+ ) ) | 
						
							| 10 | 5 9 | mpbid |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> ( B - 1 ) e. RR+ ) | 
						
							| 11 | 4 10 | rerpdivcld |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> ( ( 2 x. A ) / ( B - 1 ) ) e. RR ) | 
						
							| 12 |  | expnbnd |  |-  ( ( ( ( 2 x. A ) / ( B - 1 ) ) e. RR /\ B e. RR /\ 1 < B ) -> E. n e. NN ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) | 
						
							| 13 | 11 7 5 12 | syl3anc |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> E. n e. NN ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) | 
						
							| 14 |  | 2nn0 |  |-  2 e. NN0 | 
						
							| 15 |  | nnnn0 |  |-  ( n e. NN -> n e. NN0 ) | 
						
							| 16 | 15 | ad2antrl |  |-  ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) -> n e. NN0 ) | 
						
							| 17 |  | nn0mulcl |  |-  ( ( 2 e. NN0 /\ n e. NN0 ) -> ( 2 x. n ) e. NN0 ) | 
						
							| 18 | 14 16 17 | sylancr |  |-  ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) -> ( 2 x. n ) e. NN0 ) | 
						
							| 19 | 2 | ad2antrr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> A e. RR ) | 
						
							| 20 |  | 2nn |  |-  2 e. NN | 
						
							| 21 |  | simprl |  |-  ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) -> n e. NN ) | 
						
							| 22 |  | nnmulcl |  |-  ( ( 2 e. NN /\ n e. NN ) -> ( 2 x. n ) e. NN ) | 
						
							| 23 | 20 21 22 | sylancr |  |-  ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) -> ( 2 x. n ) e. NN ) | 
						
							| 24 |  | eluznn |  |-  ( ( ( 2 x. n ) e. NN /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. NN ) | 
						
							| 25 | 23 24 | sylan |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. NN ) | 
						
							| 26 | 25 | nnred |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. RR ) | 
						
							| 27 | 19 26 | remulcld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( A x. k ) e. RR ) | 
						
							| 28 |  | 0re |  |-  0 e. RR | 
						
							| 29 |  | ifcl |  |-  ( ( A e. RR /\ 0 e. RR ) -> if ( 0 <_ A , A , 0 ) e. RR ) | 
						
							| 30 | 19 28 29 | sylancl |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> if ( 0 <_ A , A , 0 ) e. RR ) | 
						
							| 31 |  | remulcl |  |-  ( ( 2 e. RR /\ if ( 0 <_ A , A , 0 ) e. RR ) -> ( 2 x. if ( 0 <_ A , A , 0 ) ) e. RR ) | 
						
							| 32 | 1 30 31 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. if ( 0 <_ A , A , 0 ) ) e. RR ) | 
						
							| 33 |  | simplrl |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> n e. NN ) | 
						
							| 34 | 33 | nnred |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> n e. RR ) | 
						
							| 35 | 26 34 | resubcld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k - n ) e. RR ) | 
						
							| 36 | 32 35 | remulcld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) e. RR ) | 
						
							| 37 | 7 | ad2antrr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> B e. RR ) | 
						
							| 38 | 25 | nnnn0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. NN0 ) | 
						
							| 39 |  | reexpcl |  |-  ( ( B e. RR /\ k e. NN0 ) -> ( B ^ k ) e. RR ) | 
						
							| 40 | 37 38 39 | syl2anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B ^ k ) e. RR ) | 
						
							| 41 |  | remulcl |  |-  ( ( 2 e. RR /\ ( k - n ) e. RR ) -> ( 2 x. ( k - n ) ) e. RR ) | 
						
							| 42 | 1 35 41 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. ( k - n ) ) e. RR ) | 
						
							| 43 | 38 | nn0ge0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 <_ k ) | 
						
							| 44 |  | max1 |  |-  ( ( 0 e. RR /\ A e. RR ) -> 0 <_ if ( 0 <_ A , A , 0 ) ) | 
						
							| 45 | 28 19 44 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 <_ if ( 0 <_ A , A , 0 ) ) | 
						
							| 46 |  | remulcl |  |-  ( ( 2 e. RR /\ n e. RR ) -> ( 2 x. n ) e. RR ) | 
						
							| 47 | 1 34 46 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. n ) e. RR ) | 
						
							| 48 |  | eluzle |  |-  ( k e. ( ZZ>= ` ( 2 x. n ) ) -> ( 2 x. n ) <_ k ) | 
						
							| 49 | 48 | adantl |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. n ) <_ k ) | 
						
							| 50 | 47 26 26 49 | leadd2dd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k + ( 2 x. n ) ) <_ ( k + k ) ) | 
						
							| 51 | 26 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. CC ) | 
						
							| 52 | 51 | 2timesd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. k ) = ( k + k ) ) | 
						
							| 53 | 50 52 | breqtrrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k + ( 2 x. n ) ) <_ ( 2 x. k ) ) | 
						
							| 54 |  | remulcl |  |-  ( ( 2 e. RR /\ k e. RR ) -> ( 2 x. k ) e. RR ) | 
						
							| 55 | 1 26 54 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. k ) e. RR ) | 
						
							| 56 |  | leaddsub |  |-  ( ( k e. RR /\ ( 2 x. n ) e. RR /\ ( 2 x. k ) e. RR ) -> ( ( k + ( 2 x. n ) ) <_ ( 2 x. k ) <-> k <_ ( ( 2 x. k ) - ( 2 x. n ) ) ) ) | 
						
							| 57 | 26 47 55 56 | syl3anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( k + ( 2 x. n ) ) <_ ( 2 x. k ) <-> k <_ ( ( 2 x. k ) - ( 2 x. n ) ) ) ) | 
						
							| 58 | 53 57 | mpbid |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k <_ ( ( 2 x. k ) - ( 2 x. n ) ) ) | 
						
							| 59 |  | 2cnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 2 e. CC ) | 
						
							| 60 | 34 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> n e. CC ) | 
						
							| 61 | 59 51 60 | subdid |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. ( k - n ) ) = ( ( 2 x. k ) - ( 2 x. n ) ) ) | 
						
							| 62 | 58 61 | breqtrrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k <_ ( 2 x. ( k - n ) ) ) | 
						
							| 63 |  | max2 |  |-  ( ( 0 e. RR /\ A e. RR ) -> A <_ if ( 0 <_ A , A , 0 ) ) | 
						
							| 64 | 28 19 63 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> A <_ if ( 0 <_ A , A , 0 ) ) | 
						
							| 65 | 26 42 19 30 43 45 62 64 | lemul12bd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k x. A ) <_ ( ( 2 x. ( k - n ) ) x. if ( 0 <_ A , A , 0 ) ) ) | 
						
							| 66 | 19 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> A e. CC ) | 
						
							| 67 | 66 51 | mulcomd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( A x. k ) = ( k x. A ) ) | 
						
							| 68 | 30 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> if ( 0 <_ A , A , 0 ) e. CC ) | 
						
							| 69 | 35 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k - n ) e. CC ) | 
						
							| 70 | 59 68 69 | mul32d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) = ( ( 2 x. ( k - n ) ) x. if ( 0 <_ A , A , 0 ) ) ) | 
						
							| 71 | 65 67 70 | 3brtr4d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( A x. k ) <_ ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) ) | 
						
							| 72 | 10 | ad2antrr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B - 1 ) e. RR+ ) | 
						
							| 73 | 72 | rpred |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B - 1 ) e. RR ) | 
						
							| 74 | 73 35 | remulcld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( B - 1 ) x. ( k - n ) ) e. RR ) | 
						
							| 75 | 33 | nnnn0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> n e. NN0 ) | 
						
							| 76 |  | reexpcl |  |-  ( ( B e. RR /\ n e. NN0 ) -> ( B ^ n ) e. RR ) | 
						
							| 77 | 37 75 76 | syl2anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B ^ n ) e. RR ) | 
						
							| 78 | 74 77 | remulcld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( B - 1 ) x. ( k - n ) ) x. ( B ^ n ) ) e. RR ) | 
						
							| 79 |  | simplrr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) | 
						
							| 80 | 1 19 3 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. A ) e. RR ) | 
						
							| 81 | 80 77 72 | ltdivmuld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) <-> ( 2 x. A ) < ( ( B - 1 ) x. ( B ^ n ) ) ) ) | 
						
							| 82 | 79 81 | mpbid |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. A ) < ( ( B - 1 ) x. ( B ^ n ) ) ) | 
						
							| 83 | 5 | ad2antrr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 1 < B ) | 
						
							| 84 |  | posdif |  |-  ( ( 1 e. RR /\ B e. RR ) -> ( 1 < B <-> 0 < ( B - 1 ) ) ) | 
						
							| 85 | 6 37 84 | sylancr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 1 < B <-> 0 < ( B - 1 ) ) ) | 
						
							| 86 | 83 85 | mpbid |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 < ( B - 1 ) ) | 
						
							| 87 | 33 | nnzd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> n e. ZZ ) | 
						
							| 88 | 28 | a1i |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 e. RR ) | 
						
							| 89 | 6 | a1i |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 1 e. RR ) | 
						
							| 90 |  | 0lt1 |  |-  0 < 1 | 
						
							| 91 | 90 | a1i |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 < 1 ) | 
						
							| 92 | 88 89 37 91 83 | lttrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 < B ) | 
						
							| 93 |  | expgt0 |  |-  ( ( B e. RR /\ n e. ZZ /\ 0 < B ) -> 0 < ( B ^ n ) ) | 
						
							| 94 | 37 87 92 93 | syl3anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 < ( B ^ n ) ) | 
						
							| 95 | 73 77 86 94 | mulgt0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 < ( ( B - 1 ) x. ( B ^ n ) ) ) | 
						
							| 96 |  | oveq2 |  |-  ( A = if ( 0 <_ A , A , 0 ) -> ( 2 x. A ) = ( 2 x. if ( 0 <_ A , A , 0 ) ) ) | 
						
							| 97 | 96 | breq1d |  |-  ( A = if ( 0 <_ A , A , 0 ) -> ( ( 2 x. A ) < ( ( B - 1 ) x. ( B ^ n ) ) <-> ( 2 x. if ( 0 <_ A , A , 0 ) ) < ( ( B - 1 ) x. ( B ^ n ) ) ) ) | 
						
							| 98 |  | 2t0e0 |  |-  ( 2 x. 0 ) = 0 | 
						
							| 99 |  | oveq2 |  |-  ( 0 = if ( 0 <_ A , A , 0 ) -> ( 2 x. 0 ) = ( 2 x. if ( 0 <_ A , A , 0 ) ) ) | 
						
							| 100 | 98 99 | eqtr3id |  |-  ( 0 = if ( 0 <_ A , A , 0 ) -> 0 = ( 2 x. if ( 0 <_ A , A , 0 ) ) ) | 
						
							| 101 | 100 | breq1d |  |-  ( 0 = if ( 0 <_ A , A , 0 ) -> ( 0 < ( ( B - 1 ) x. ( B ^ n ) ) <-> ( 2 x. if ( 0 <_ A , A , 0 ) ) < ( ( B - 1 ) x. ( B ^ n ) ) ) ) | 
						
							| 102 | 97 101 | ifboth |  |-  ( ( ( 2 x. A ) < ( ( B - 1 ) x. ( B ^ n ) ) /\ 0 < ( ( B - 1 ) x. ( B ^ n ) ) ) -> ( 2 x. if ( 0 <_ A , A , 0 ) ) < ( ( B - 1 ) x. ( B ^ n ) ) ) | 
						
							| 103 | 82 95 102 | syl2anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. if ( 0 <_ A , A , 0 ) ) < ( ( B - 1 ) x. ( B ^ n ) ) ) | 
						
							| 104 | 73 77 | remulcld |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( B - 1 ) x. ( B ^ n ) ) e. RR ) | 
						
							| 105 |  | simpr |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. ( ZZ>= ` ( 2 x. n ) ) ) | 
						
							| 106 | 60 | 2timesd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( 2 x. n ) = ( n + n ) ) | 
						
							| 107 | 106 | fveq2d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ZZ>= ` ( 2 x. n ) ) = ( ZZ>= ` ( n + n ) ) ) | 
						
							| 108 | 105 107 | eleqtrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. ( ZZ>= ` ( n + n ) ) ) | 
						
							| 109 |  | eluzsub |  |-  ( ( n e. ZZ /\ n e. ZZ /\ k e. ( ZZ>= ` ( n + n ) ) ) -> ( k - n ) e. ( ZZ>= ` n ) ) | 
						
							| 110 | 87 87 108 109 | syl3anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k - n ) e. ( ZZ>= ` n ) ) | 
						
							| 111 |  | eluznn |  |-  ( ( n e. NN /\ ( k - n ) e. ( ZZ>= ` n ) ) -> ( k - n ) e. NN ) | 
						
							| 112 | 33 110 111 | syl2anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k - n ) e. NN ) | 
						
							| 113 | 112 | nngt0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 < ( k - n ) ) | 
						
							| 114 |  | ltmul1 |  |-  ( ( ( 2 x. if ( 0 <_ A , A , 0 ) ) e. RR /\ ( ( B - 1 ) x. ( B ^ n ) ) e. RR /\ ( ( k - n ) e. RR /\ 0 < ( k - n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) < ( ( B - 1 ) x. ( B ^ n ) ) <-> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) < ( ( ( B - 1 ) x. ( B ^ n ) ) x. ( k - n ) ) ) ) | 
						
							| 115 | 32 104 35 113 114 | syl112anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) < ( ( B - 1 ) x. ( B ^ n ) ) <-> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) < ( ( ( B - 1 ) x. ( B ^ n ) ) x. ( k - n ) ) ) ) | 
						
							| 116 | 103 115 | mpbid |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) < ( ( ( B - 1 ) x. ( B ^ n ) ) x. ( k - n ) ) ) | 
						
							| 117 | 73 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B - 1 ) e. CC ) | 
						
							| 118 | 77 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B ^ n ) e. CC ) | 
						
							| 119 | 117 118 69 | mul32d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( B - 1 ) x. ( B ^ n ) ) x. ( k - n ) ) = ( ( ( B - 1 ) x. ( k - n ) ) x. ( B ^ n ) ) ) | 
						
							| 120 | 116 119 | breqtrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) < ( ( ( B - 1 ) x. ( k - n ) ) x. ( B ^ n ) ) ) | 
						
							| 121 |  | peano2re |  |-  ( ( ( B - 1 ) x. ( k - n ) ) e. RR -> ( ( ( B - 1 ) x. ( k - n ) ) + 1 ) e. RR ) | 
						
							| 122 | 74 121 | syl |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( B - 1 ) x. ( k - n ) ) + 1 ) e. RR ) | 
						
							| 123 | 112 | nnnn0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( k - n ) e. NN0 ) | 
						
							| 124 |  | reexpcl |  |-  ( ( B e. RR /\ ( k - n ) e. NN0 ) -> ( B ^ ( k - n ) ) e. RR ) | 
						
							| 125 | 37 123 124 | syl2anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B ^ ( k - n ) ) e. RR ) | 
						
							| 126 | 74 | ltp1d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( B - 1 ) x. ( k - n ) ) < ( ( ( B - 1 ) x. ( k - n ) ) + 1 ) ) | 
						
							| 127 | 88 37 92 | ltled |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> 0 <_ B ) | 
						
							| 128 |  | bernneq2 |  |-  ( ( B e. RR /\ ( k - n ) e. NN0 /\ 0 <_ B ) -> ( ( ( B - 1 ) x. ( k - n ) ) + 1 ) <_ ( B ^ ( k - n ) ) ) | 
						
							| 129 | 37 123 127 128 | syl3anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( B - 1 ) x. ( k - n ) ) + 1 ) <_ ( B ^ ( k - n ) ) ) | 
						
							| 130 | 74 122 125 126 129 | ltletrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( B - 1 ) x. ( k - n ) ) < ( B ^ ( k - n ) ) ) | 
						
							| 131 | 37 | recnd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> B e. CC ) | 
						
							| 132 | 92 | gt0ne0d |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> B =/= 0 ) | 
						
							| 133 |  | eluzelz |  |-  ( k e. ( ZZ>= ` ( 2 x. n ) ) -> k e. ZZ ) | 
						
							| 134 | 133 | adantl |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> k e. ZZ ) | 
						
							| 135 |  | expsub |  |-  ( ( ( B e. CC /\ B =/= 0 ) /\ ( k e. ZZ /\ n e. ZZ ) ) -> ( B ^ ( k - n ) ) = ( ( B ^ k ) / ( B ^ n ) ) ) | 
						
							| 136 | 131 132 134 87 135 | syl22anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( B ^ ( k - n ) ) = ( ( B ^ k ) / ( B ^ n ) ) ) | 
						
							| 137 | 130 136 | breqtrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( B - 1 ) x. ( k - n ) ) < ( ( B ^ k ) / ( B ^ n ) ) ) | 
						
							| 138 |  | ltmuldiv |  |-  ( ( ( ( B - 1 ) x. ( k - n ) ) e. RR /\ ( B ^ k ) e. RR /\ ( ( B ^ n ) e. RR /\ 0 < ( B ^ n ) ) ) -> ( ( ( ( B - 1 ) x. ( k - n ) ) x. ( B ^ n ) ) < ( B ^ k ) <-> ( ( B - 1 ) x. ( k - n ) ) < ( ( B ^ k ) / ( B ^ n ) ) ) ) | 
						
							| 139 | 74 40 77 94 138 | syl112anc |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( ( B - 1 ) x. ( k - n ) ) x. ( B ^ n ) ) < ( B ^ k ) <-> ( ( B - 1 ) x. ( k - n ) ) < ( ( B ^ k ) / ( B ^ n ) ) ) ) | 
						
							| 140 | 137 139 | mpbird |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( ( B - 1 ) x. ( k - n ) ) x. ( B ^ n ) ) < ( B ^ k ) ) | 
						
							| 141 | 36 78 40 120 140 | lttrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( ( 2 x. if ( 0 <_ A , A , 0 ) ) x. ( k - n ) ) < ( B ^ k ) ) | 
						
							| 142 | 27 36 40 71 141 | lelttrd |  |-  ( ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) /\ k e. ( ZZ>= ` ( 2 x. n ) ) ) -> ( A x. k ) < ( B ^ k ) ) | 
						
							| 143 | 142 | ralrimiva |  |-  ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) -> A. k e. ( ZZ>= ` ( 2 x. n ) ) ( A x. k ) < ( B ^ k ) ) | 
						
							| 144 |  | fveq2 |  |-  ( j = ( 2 x. n ) -> ( ZZ>= ` j ) = ( ZZ>= ` ( 2 x. n ) ) ) | 
						
							| 145 | 144 | raleqdv |  |-  ( j = ( 2 x. n ) -> ( A. k e. ( ZZ>= ` j ) ( A x. k ) < ( B ^ k ) <-> A. k e. ( ZZ>= ` ( 2 x. n ) ) ( A x. k ) < ( B ^ k ) ) ) | 
						
							| 146 | 145 | rspcev |  |-  ( ( ( 2 x. n ) e. NN0 /\ A. k e. ( ZZ>= ` ( 2 x. n ) ) ( A x. k ) < ( B ^ k ) ) -> E. j e. NN0 A. k e. ( ZZ>= ` j ) ( A x. k ) < ( B ^ k ) ) | 
						
							| 147 | 18 143 146 | syl2anc |  |-  ( ( ( A e. RR /\ B e. RR /\ 1 < B ) /\ ( n e. NN /\ ( ( 2 x. A ) / ( B - 1 ) ) < ( B ^ n ) ) ) -> E. j e. NN0 A. k e. ( ZZ>= ` j ) ( A x. k ) < ( B ^ k ) ) | 
						
							| 148 | 13 147 | rexlimddv |  |-  ( ( A e. RR /\ B e. RR /\ 1 < B ) -> E. j e. NN0 A. k e. ( ZZ>= ` j ) ( A x. k ) < ( B ^ k ) ) |