text: #ifndef INV_LAPLACE_H
  #define INV_LAPLACE_H
  
  #include <complex.h>
  
  vector* ilt_euler(double complex (*)(double complex, void*), vector*, int, void*);
  double complex laplace(double complex (*)(double complex, void*),
                         double complex, void *);
  double l2errornorm(vector*, vector*, vector*);
  
  #endif
  