.. attention:: 
   Because of licensing restrictions imposed by Daresbury Laboratory, it is 
   impossible to supply this XOP in either binary form or with all the necessary 
   source code.

 * You are responsible for complying with the terms of the CCP4 Program 
   Suite Licence Agreement, as explained at 
   http://www.ccp4.ac.uk/ccp4license.php

 * Obtain the CCP4 source code distribution from 
   http://www.ccp4.ac.uk/download.php
   (It is only strictly necessary to obtain `lib/src/pack_c.c` and 
   `lib/src/pack_c.h`)

   .. note:: precompiled binaries of the CCP4 libraries are not helpful as 
             they do not export the necessary symbols.

 * Xcode: 
   * Open the CCP4XOP group at the top of the Groups & Files list
   * Open the Source folder in the CCP4XOP group
   * Select the pack_c.c file 
   * Choose File->Get Info
   * Choose the General tab
   * Click the Choose button next to the Path and locate 
     `lib/src/pack_c.c` in the CCP4 source code distribution
   * Choose Build->Build
   * Make an alias for the 
     `CCP4XOP/Xcode/build/(Debug|Release)/CCP4XOP.xop` package folder and 
     put the alias in your `Igor Extensions` folder.
   * Make an alias for the `CCP4XOP/CCP4XOP Help.ihf` file and put the 
     alias in your `Igor Extensions` folder.