void diff_face_(integer *n, realtype *dt, realtype *cnpar, realtype *h, integer *bcup, integer *bcdw, realtype *yup, realtype *ydw, realtype *nuy, realtype *lsour, realtype *qsour, realtype *y)
static void util_diff_face(integer *n, realtype *dt, realtype *cnpar, realtype *h, integer *bcup, integer *bcdw, realtype *yup, realtype *ydw, realtype *nuy, realtype *lsour, realtype *qsour, realtype *y)