typedef enum {
  m1d_kind_POLY = 0,  /* Polynomials. */
  m1d_kind_TRIG = 1,  /* Cosine and sine trigonometric series. */
  m1d_kind_BSPL = 2,  /* Minimal-degree B-spline-like. */
  m1d_kind_HERM = 3,  /* Hermite-style pulses. */
  m1d_kind_UPAR = 4   /* Compact partition-of-unity pulses. */
} m1d_kind_t;
  
char *brep_kind_tag(brep_kind_t bkind);
  /* Returns a fixed character string that identifies the basis
    kind {bkind}: "POLY", "TRIG", etc. */

typedef struct brep_family_t {
  brep_kind_t bkind; /* Basis kind. */
  brep_degree_t g;   /* Max degree or number of terms. */
  brep_cont_t c;     /* Continuity order. */
} brep_family_t;
  /* Describes a basis of mother functions with continuity {c},
    whose domain is the whole real line.  The parameter {g}
    is the maximum degree or order of the basis elements,
    depending on the {bkind}. */

void brep_family_print(FILE *wr, brep_family_t *fam);
  /* Prints out the description of mother basis {fam} to {wr}.  */
  
brep_mother_num_t brep_family_num(brep_family_t *fam);
  /* Number {num} of elements in the mother basis {fam}. 
    The elements are indexed {0..num-1}. */

typedef struct brep_basis_t {
  brep_family_t fam; /* Family of mother functions. */
  int gsz;          /* Number of intervals. */
  interval_t dom;   /* Argument domain. */
  bool_t wrap;      /* TRUE iff the domain is periodic. */
} brep_basis_t;
  /* Describes a basis of functions defined over the domain {dom},
    whose elements are obtained by expanding and translating functions
    of mother basis {fam} over a regular grid. */
  
char *brep_basis_tag(brep_basis_t *bas);
  /* Creates a new char string that identifies the basis {bas}. */

brep_grid_size_t brep_element_supp_count
  ( brep_family_t *fam, 
    brep_mother_index_t pix, 
    brep_grid_size_t gsz,
    bool_t wrap
  );
  /* Number of cells where a basis element with mother element {fam,pix}
    may be nonzero, assuming a grid with {gsz} cells with
    periodicity flag {wrap}. 
    
    If {wrap} is FALSE, the result is simply the support count {msn}
    of the mother element. If {wrap} is TRUE, the result is the
    smallest of {gsz} and {msn}. */
  

typedef uint64_t brep_cell_index_t;
  /* Identifies a cell in some (multi)grid. */

/* MULTISCALE BASES */

typedef int32_t brep_rank_t;
  /* Identifies a layer in a multigrid, or the depth of a node
    in a binary tree, etc. It may also be a relative rank (i.e.
    difference of two ranks). */