pn_vis
pn->pn_vis = vis;
pn->pn_vis = vis;
pn->pn_vis = vis;
pfs_vis_t pn_vis;
if (pn->pn_vis == NULL)
return ((pn->pn_vis)(PFS_VIS_ARGNAMES));
return (pn_vis(td, proc, pn));
PFS_RETURN (pn_vis(td, NULL, pn));
visible = pn_vis(td, NULL, *pn);