new0
#define new_n(n) new0(n, NULL, NULL, 0, NULL)
#define new_nx(n, x) new0(n, NULL, NULL, 0, x)
#define new_ns(n, s) new0(n, s, NULL, 0, NULL)
#define new_si(s, i) new0(NULL, s, NULL, i, NULL)
#define new_nsi(n,s,i) new0(n, s, NULL, i, NULL)
#define new_np(n, p) new0(n, NULL, p, 0, NULL)
#define new_s(s) new0(NULL, s, NULL, 0, NULL)
#define new_p(p) new0(NULL, NULL, p, 0, NULL)
#define new_px(p, x) new0(NULL, NULL, p, 0, x)
#define fx_atom(s) new0(s, NULL, NULL, FX_ATOM, NULL)
#define fx_not(e) new0(NULL, NULL, NULL, FX_NOT, e)
#define fx_and(e1, e2) new0(NULL, NULL, e1, FX_AND, e2)
#define fx_or(e1, e2) new0(NULL, NULL, e1, FX_OR, e2)