Bignum b = malloc((orig[0]+1)*sizeof(unsigned short));
Bignum b = smalloc((orig[0]+1)*sizeof(unsigned short));
Bignum copybn(Bignum orig) {    Bignum b = malloc((orig[0]+1)*sizeof(unsigned short));    if (!b)	abort();		       /* FIXME */    memcpy(b, orig, (orig[0]+1)*sizeof(*b));    return b;}