1 | #include "erfa.h"
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2 |
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3 | void eraPn00b(double date1, double date2,
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4 | double *dpsi, double *deps, double *epsa,
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5 | double rb[3][3], double rp[3][3], double rbp[3][3],
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6 | double rn[3][3], double rbpn[3][3])
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7 | /*
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8 | ** - - - - - - - - -
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9 | ** e r a P n 0 0 b
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10 | ** - - - - - - - - -
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11 | **
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12 | ** Precession-nutation, IAU 2000B model: a multi-purpose function,
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13 | ** supporting classical (equinox-based) use directly and CIO-based
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14 | ** use indirectly.
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15 | **
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16 | ** Given:
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17 | ** date1,date2 double TT as a 2-part Julian Date (Note 1)
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18 | **
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19 | ** Returned:
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20 | ** dpsi,deps double nutation (Note 2)
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21 | ** epsa double mean obliquity (Note 3)
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22 | ** rb double[3][3] frame bias matrix (Note 4)
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23 | ** rp double[3][3] precession matrix (Note 5)
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24 | ** rbp double[3][3] bias-precession matrix (Note 6)
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25 | ** rn double[3][3] nutation matrix (Note 7)
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26 | ** rbpn double[3][3] GCRS-to-true matrix (Notes 8,9)
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27 | **
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28 | ** Notes:
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29 | **
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30 | ** 1) The TT date date1+date2 is a Julian Date, apportioned in any
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31 | ** convenient way between the two arguments. For example,
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32 | ** JD(TT)=2450123.7 could be expressed in any of these ways,
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33 | ** among others:
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34 | **
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35 | ** date1 date2
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36 | **
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37 | ** 2450123.7 0.0 (JD method)
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38 | ** 2451545.0 -1421.3 (J2000 method)
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39 | ** 2400000.5 50123.2 (MJD method)
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40 | ** 2450123.5 0.2 (date & time method)
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41 | **
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42 | ** The JD method is the most natural and convenient to use in
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43 | ** cases where the loss of several decimal digits of resolution
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44 | ** is acceptable. The J2000 method is best matched to the way
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45 | ** the argument is handled internally and will deliver the
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46 | ** optimum resolution. The MJD method and the date & time methods
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47 | ** are both good compromises between resolution and convenience.
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48 | **
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49 | ** 2) The nutation components (luni-solar + planetary, IAU 2000B) in
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50 | ** longitude and obliquity are in radians and with respect to the
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51 | ** equinox and ecliptic of date. For more accurate results, but
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52 | ** at the cost of increased computation, use the eraPn00a function.
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53 | ** For the utmost accuracy, use the eraPn00 function, where the
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54 | ** nutation components are caller-specified.
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55 | **
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56 | ** 3) The mean obliquity is consistent with the IAU 2000 precession.
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57 | **
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58 | ** 4) The matrix rb transforms vectors from GCRS to J2000.0 mean
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59 | ** equator and equinox by applying frame bias.
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60 | **
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61 | ** 5) The matrix rp transforms vectors from J2000.0 mean equator and
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62 | ** equinox to mean equator and equinox of date by applying
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63 | ** precession.
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64 | **
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65 | ** 6) The matrix rbp transforms vectors from GCRS to mean equator and
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66 | ** equinox of date by applying frame bias then precession. It is
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67 | ** the product rp x rb.
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68 | **
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69 | ** 7) The matrix rn transforms vectors from mean equator and equinox
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70 | ** of date to true equator and equinox of date by applying the
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71 | ** nutation (luni-solar + planetary).
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72 | **
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73 | ** 8) The matrix rbpn transforms vectors from GCRS to true equator and
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74 | ** equinox of date. It is the product rn x rbp, applying frame
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75 | ** bias, precession and nutation in that order.
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76 | **
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77 | ** 9) The X,Y,Z coordinates of the IAU 2000B Celestial Intermediate
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78 | ** Pole are elements (3,1-3) of the GCRS-to-true matrix,
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79 | ** i.e. rbpn[2][0-2].
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80 | **
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81 | ** 10) It is permissible to re-use the same array in the returned
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82 | ** arguments. The arrays are filled in the stated order.
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83 | **
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84 | ** Called:
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85 | ** eraNut00b nutation, IAU 2000B
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86 | ** eraPn00 bias/precession/nutation results, IAU 2000
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87 | **
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88 | ** Reference:
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89 | **
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90 | ** Capitaine, N., Chapront, J., Lambert, S. and Wallace, P.,
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91 | ** "Expressions for the Celestial Intermediate Pole and Celestial
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92 | ** Ephemeris Origin consistent with the IAU 2000A precession-
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93 | ** nutation model", Astron.Astrophys. 400, 1145-1154 (2003).
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94 | **
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95 | ** n.b. The celestial ephemeris origin (CEO) was renamed "celestial
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96 | ** intermediate origin" (CIO) by IAU 2006 Resolution 2.
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97 | **
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98 | ** Copyright (C) 2013-2015, NumFOCUS Foundation.
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99 | ** Derived, with permission, from the SOFA library. See notes at end of file.
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100 | */
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101 | {
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102 | /* Nutation. */
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103 | eraNut00b(date1, date2, dpsi, deps);
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104 |
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105 | /* Remaining results. */
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106 | eraPn00(date1, date2, *dpsi, *deps, epsa, rb, rp, rbp, rn, rbpn);
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107 |
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108 | return;
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109 |
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110 | }
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111 | /*----------------------------------------------------------------------
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112 | **
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113 | **
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114 | ** Copyright (C) 2013-2015, NumFOCUS Foundation.
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115 | ** All rights reserved.
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116 | **
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117 | ** This library is derived, with permission, from the International
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118 | ** Astronomical Union's "Standards of Fundamental Astronomy" library,
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119 | ** available from http://www.iausofa.org.
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120 | **
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121 | ** The ERFA version is intended to retain identical functionality to
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122 | ** the SOFA library, but made distinct through different function and
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123 | ** file names, as set out in the SOFA license conditions. The SOFA
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124 | ** original has a role as a reference standard for the IAU and IERS,
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125 | ** and consequently redistribution is permitted only in its unaltered
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126 | ** state. The ERFA version is not subject to this restriction and
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127 | ** therefore can be included in distributions which do not support the
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128 | ** concept of "read only" software.
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129 | **
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130 | ** Although the intent is to replicate the SOFA API (other than
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131 | ** replacement of prefix names) and results (with the exception of
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132 | ** bugs; any that are discovered will be fixed), SOFA is not
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133 | ** responsible for any errors found in this version of the library.
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134 | **
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135 | ** If you wish to acknowledge the SOFA heritage, please acknowledge
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136 | ** that you are using a library derived from SOFA, rather than SOFA
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137 | ** itself.
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138 | **
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139 | **
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140 | ** TERMS AND CONDITIONS
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141 | **
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142 | ** Redistribution and use in source and binary forms, with or without
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143 | ** modification, are permitted provided that the following conditions
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144 | ** are met:
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145 | **
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146 | ** 1 Redistributions of source code must retain the above copyright
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147 | ** notice, this list of conditions and the following disclaimer.
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148 | **
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149 | ** 2 Redistributions in binary form must reproduce the above copyright
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150 | ** notice, this list of conditions and the following disclaimer in
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151 | ** the documentation and/or other materials provided with the
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152 | ** distribution.
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153 | **
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154 | ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
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155 | ** the International Astronomical Union nor the names of its
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156 | ** contributors may be used to endorse or promote products derived
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157 | ** from this software without specific prior written permission.
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158 | **
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159 | ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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160 | ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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161 | ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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162 | ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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163 | ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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164 | ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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165 | ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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166 | ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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167 | ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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168 | ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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169 | ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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170 | ** POSSIBILITY OF SUCH DAMAGE.
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171 | **
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172 | */
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