| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							0zd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> 0 e. ZZ ) | 
						
						
							| 2 | 
							
								
							 | 
							pire | 
							 |-  _pi e. RR  | 
						
						
							| 3 | 
							
								2
							 | 
							renegcli | 
							 |-  -u _pi e. RR  | 
						
						
							| 4 | 
							
								
							 | 
							iccssre | 
							 |-  ( ( -u _pi e. RR /\ _pi e. RR ) -> ( -u _pi [,] _pi ) C_ RR )  | 
						
						
							| 5 | 
							
								3 2 4
							 | 
							mp2an | 
							 |-  ( -u _pi [,] _pi ) C_ RR  | 
						
						
							| 6 | 
							
								
							 | 
							eldifi | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> A e. ( -u _pi [,] _pi ) ) | 
						
						
							| 7 | 
							
								5 6
							 | 
							sselid | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> A e. RR ) | 
						
						
							| 8 | 
							
								7
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> A e. RR ) | 
						
						
							| 9 | 
							
								
							 | 
							2re | 
							 |-  2 e. RR  | 
						
						
							| 10 | 
							
								9 2
							 | 
							remulcli | 
							 |-  ( 2 x. _pi ) e. RR  | 
						
						
							| 11 | 
							
								10
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> ( 2 x. _pi ) e. RR ) | 
						
						
							| 12 | 
							
								
							 | 
							simpr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> 0 < A ) | 
						
						
							| 13 | 
							
								
							 | 
							2pos | 
							 |-  0 < 2  | 
						
						
							| 14 | 
							
								
							 | 
							pipos | 
							 |-  0 < _pi  | 
						
						
							| 15 | 
							
								9 2 13 14
							 | 
							mulgt0ii | 
							 |-  0 < ( 2 x. _pi )  | 
						
						
							| 16 | 
							
								15
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> 0 < ( 2 x. _pi ) ) | 
						
						
							| 17 | 
							
								8 11 12 16
							 | 
							divgt0d | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> 0 < ( A / ( 2 x. _pi ) ) ) | 
						
						
							| 18 | 
							
								11 16
							 | 
							elrpd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> ( 2 x. _pi ) e. RR+ ) | 
						
						
							| 19 | 
							
								2
							 | 
							a1i | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> _pi e. RR ) | 
						
						
							| 20 | 
							
								10
							 | 
							a1i | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> ( 2 x. _pi ) e. RR ) | 
						
						
							| 21 | 
							
								3
							 | 
							rexri | 
							 |-  -u _pi e. RR*  | 
						
						
							| 22 | 
							
								21
							 | 
							a1i | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -u _pi e. RR* ) | 
						
						
							| 23 | 
							
								19
							 | 
							rexrd | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> _pi e. RR* ) | 
						
						
							| 24 | 
							
								
							 | 
							iccleub | 
							 |-  ( ( -u _pi e. RR* /\ _pi e. RR* /\ A e. ( -u _pi [,] _pi ) ) -> A <_ _pi )  | 
						
						
							| 25 | 
							
								22 23 6 24
							 | 
							syl3anc | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> A <_ _pi ) | 
						
						
							| 26 | 
							
								
							 | 
							pirp | 
							 |-  _pi e. RR+  | 
						
						
							| 27 | 
							
								
							 | 
							2timesgt | 
							 |-  ( _pi e. RR+ -> _pi < ( 2 x. _pi ) )  | 
						
						
							| 28 | 
							
								26 27
							 | 
							mp1i | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> _pi < ( 2 x. _pi ) ) | 
						
						
							| 29 | 
							
								7 19 20 25 28
							 | 
							lelttrd | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> A < ( 2 x. _pi ) ) | 
						
						
							| 30 | 
							
								29
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> A < ( 2 x. _pi ) ) | 
						
						
							| 31 | 
							
								8 11 18 30
							 | 
							ltdiv1dd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> ( A / ( 2 x. _pi ) ) < ( ( 2 x. _pi ) / ( 2 x. _pi ) ) ) | 
						
						
							| 32 | 
							
								10
							 | 
							recni | 
							 |-  ( 2 x. _pi ) e. CC  | 
						
						
							| 33 | 
							
								10 15
							 | 
							gt0ne0ii | 
							 |-  ( 2 x. _pi ) =/= 0  | 
						
						
							| 34 | 
							
								32 33
							 | 
							dividi | 
							 |-  ( ( 2 x. _pi ) / ( 2 x. _pi ) ) = 1  | 
						
						
							| 35 | 
							
								31 34
							 | 
							breqtrdi | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> ( A / ( 2 x. _pi ) ) < 1 ) | 
						
						
							| 36 | 
							
								
							 | 
							0p1e1 | 
							 |-  ( 0 + 1 ) = 1  | 
						
						
							| 37 | 
							
								35 36
							 | 
							breqtrrdi | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> ( A / ( 2 x. _pi ) ) < ( 0 + 1 ) ) | 
						
						
							| 38 | 
							
								
							 | 
							btwnnz | 
							 |-  ( ( 0 e. ZZ /\ 0 < ( A / ( 2 x. _pi ) ) /\ ( A / ( 2 x. _pi ) ) < ( 0 + 1 ) ) -> -. ( A / ( 2 x. _pi ) ) e. ZZ )  | 
						
						
							| 39 | 
							
								1 17 37 38
							 | 
							syl3anc | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ 0 < A ) -> -. ( A / ( 2 x. _pi ) ) e. ZZ ) | 
						
						
							| 40 | 
							
								
							 | 
							simpl | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> A e. ( ( -u _pi [,] _pi ) \ { 0 } ) ) | 
						
						
							| 41 | 
							
								7
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> A e. RR ) | 
						
						
							| 42 | 
							
								
							 | 
							0red | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> 0 e. RR ) | 
						
						
							| 43 | 
							
								
							 | 
							simpr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> -. 0 < A ) | 
						
						
							| 44 | 
							
								41 42 43
							 | 
							nltled | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> A <_ 0 ) | 
						
						
							| 45 | 
							
								
							 | 
							eldifsni | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> A =/= 0 ) | 
						
						
							| 46 | 
							
								45
							 | 
							necomd | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> 0 =/= A ) | 
						
						
							| 47 | 
							
								46
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> 0 =/= A ) | 
						
						
							| 48 | 
							
								41 42 44 47
							 | 
							leneltd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> A < 0 ) | 
						
						
							| 49 | 
							
								
							 | 
							neg1z | 
							 |-  -u 1 e. ZZ  | 
						
						
							| 50 | 
							
								49
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -u 1 e. ZZ ) | 
						
						
							| 51 | 
							
								33
							 | 
							a1i | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> ( 2 x. _pi ) =/= 0 ) | 
						
						
							| 52 | 
							
								7 20 51
							 | 
							redivcld | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> ( A / ( 2 x. _pi ) ) e. RR ) | 
						
						
							| 53 | 
							
								52
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( A / ( 2 x. _pi ) ) e. RR ) | 
						
						
							| 54 | 
							
								
							 | 
							1red | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> 1 e. RR ) | 
						
						
							| 55 | 
							
								7
							 | 
							recnd | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> A e. CC ) | 
						
						
							| 56 | 
							
								55
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> A e. CC ) | 
						
						
							| 57 | 
							
								32
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( 2 x. _pi ) e. CC ) | 
						
						
							| 58 | 
							
								33
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( 2 x. _pi ) =/= 0 ) | 
						
						
							| 59 | 
							
								56 57 58
							 | 
							divnegd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -u ( A / ( 2 x. _pi ) ) = ( -u A / ( 2 x. _pi ) ) ) | 
						
						
							| 60 | 
							
								7
							 | 
							renegcld | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -u A e. RR ) | 
						
						
							| 61 | 
							
								60
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -u A e. RR ) | 
						
						
							| 62 | 
							
								10
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( 2 x. _pi ) e. RR ) | 
						
						
							| 63 | 
							
								
							 | 
							2rp | 
							 |-  2 e. RR+  | 
						
						
							| 64 | 
							
								
							 | 
							rpmulcl | 
							 |-  ( ( 2 e. RR+ /\ _pi e. RR+ ) -> ( 2 x. _pi ) e. RR+ )  | 
						
						
							| 65 | 
							
								63 26 64
							 | 
							mp2an | 
							 |-  ( 2 x. _pi ) e. RR+  | 
						
						
							| 66 | 
							
								65
							 | 
							a1i | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( 2 x. _pi ) e. RR+ ) | 
						
						
							| 67 | 
							
								
							 | 
							iccgelb | 
							 |-  ( ( -u _pi e. RR* /\ _pi e. RR* /\ A e. ( -u _pi [,] _pi ) ) -> -u _pi <_ A )  | 
						
						
							| 68 | 
							
								22 23 6 67
							 | 
							syl3anc | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -u _pi <_ A ) | 
						
						
							| 69 | 
							
								19 7 68
							 | 
							lenegcon1d | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -u A <_ _pi ) | 
						
						
							| 70 | 
							
								60 19 20 69 28
							 | 
							lelttrd | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -u A < ( 2 x. _pi ) ) | 
						
						
							| 71 | 
							
								70
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -u A < ( 2 x. _pi ) ) | 
						
						
							| 72 | 
							
								61 62 66 71
							 | 
							ltdiv1dd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( -u A / ( 2 x. _pi ) ) < ( ( 2 x. _pi ) / ( 2 x. _pi ) ) ) | 
						
						
							| 73 | 
							
								72 34
							 | 
							breqtrdi | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( -u A / ( 2 x. _pi ) ) < 1 ) | 
						
						
							| 74 | 
							
								59 73
							 | 
							eqbrtrd | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -u ( A / ( 2 x. _pi ) ) < 1 ) | 
						
						
							| 75 | 
							
								53 54 74
							 | 
							ltnegcon1d | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -u 1 < ( A / ( 2 x. _pi ) ) ) | 
						
						
							| 76 | 
							
								7
							 | 
							adantr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> A e. RR ) | 
						
						
							| 77 | 
							
								
							 | 
							simpr | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> A < 0 ) | 
						
						
							| 78 | 
							
								76 66 77
							 | 
							divlt0gt0d | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( A / ( 2 x. _pi ) ) < 0 ) | 
						
						
							| 79 | 
							
								
							 | 
							neg1cn | 
							 |-  -u 1 e. CC  | 
						
						
							| 80 | 
							
								
							 | 
							ax-1cn | 
							 |-  1 e. CC  | 
						
						
							| 81 | 
							
								79 80
							 | 
							addcomi | 
							 |-  ( -u 1 + 1 ) = ( 1 + -u 1 )  | 
						
						
							| 82 | 
							
								
							 | 
							1pneg1e0 | 
							 |-  ( 1 + -u 1 ) = 0  | 
						
						
							| 83 | 
							
								81 82
							 | 
							eqtr2i | 
							 |-  0 = ( -u 1 + 1 )  | 
						
						
							| 84 | 
							
								78 83
							 | 
							breqtrdi | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> ( A / ( 2 x. _pi ) ) < ( -u 1 + 1 ) ) | 
						
						
							| 85 | 
							
								
							 | 
							btwnnz | 
							 |-  ( ( -u 1 e. ZZ /\ -u 1 < ( A / ( 2 x. _pi ) ) /\ ( A / ( 2 x. _pi ) ) < ( -u 1 + 1 ) ) -> -. ( A / ( 2 x. _pi ) ) e. ZZ )  | 
						
						
							| 86 | 
							
								50 75 84 85
							 | 
							syl3anc | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ A < 0 ) -> -. ( A / ( 2 x. _pi ) ) e. ZZ ) | 
						
						
							| 87 | 
							
								40 48 86
							 | 
							syl2anc | 
							 |-  ( ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) /\ -. 0 < A ) -> -. ( A / ( 2 x. _pi ) ) e. ZZ ) | 
						
						
							| 88 | 
							
								39 87
							 | 
							pm2.61dan | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -. ( A / ( 2 x. _pi ) ) e. ZZ ) | 
						
						
							| 89 | 
							
								65
							 | 
							a1i | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> ( 2 x. _pi ) e. RR+ ) | 
						
						
							| 90 | 
							
								
							 | 
							mod0 | 
							 |-  ( ( A e. RR /\ ( 2 x. _pi ) e. RR+ ) -> ( ( A mod ( 2 x. _pi ) ) = 0 <-> ( A / ( 2 x. _pi ) ) e. ZZ ) )  | 
						
						
							| 91 | 
							
								7 89 90
							 | 
							syl2anc | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> ( ( A mod ( 2 x. _pi ) ) = 0 <-> ( A / ( 2 x. _pi ) ) e. ZZ ) ) | 
						
						
							| 92 | 
							
								88 91
							 | 
							mtbird | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> -. ( A mod ( 2 x. _pi ) ) = 0 ) | 
						
						
							| 93 | 
							
								92
							 | 
							neqned | 
							 |-  ( A e. ( ( -u _pi [,] _pi ) \ { 0 } ) -> ( A mod ( 2 x. _pi ) ) =/= 0 ) |