| Eigen is primarily MPL2 licensed. See COPYING.MPL2 and these links: | 
 |   http://www.mozilla.org/MPL/2.0/ | 
 |   http://www.mozilla.org/MPL/2.0/FAQ.html | 
 |  | 
 | Some files contain third-party code under BSD or LGPL licenses, whence the other | 
 | COPYING.* files here. | 
 |  | 
 | All the LGPL code is either LGPL 2.1-only, or LGPL 2.1-or-later. | 
 | For this reason, the COPYING.LGPL file contains the LGPL 2.1 text. | 
 |  | 
 | If you want to guarantee that the Eigen code that you are #including is licensed | 
 | under the MPL2 and possibly more permissive licenses (like BSD), #define this | 
 | preprocessor symbol: | 
 |   EIGEN_MPL2_ONLY | 
 | For example, with most compilers, you could add this to your project CXXFLAGS: | 
 |   -DEIGEN_MPL2_ONLY | 
 | This will cause a compilation error to be generated if you #include any code that is | 
 | LGPL licensed. |