text: #ifdef __cplusplus
  extern "C" { 
  #endif  
  
  #include "f2c.h" 
  
  int dtgevc_(char *side, char *howmny, logical *select, integer *n, doublereal *a, integer *lda, doublereal *b, integer *ldb, doublereal *vl, integer *ldvl, doublereal *vr, integer *ldvr, integer *mm, integer *m, doublereal *work, integer *info);
  
  #ifdef __cplusplus
  }
  #endif