The level-set object is represented by a primary level-set and optionally
   a secondary level-set used to represent fractures (if p(x) is the primary
   level-set function and s(x) is the secondary level-set, the crack is
   defined by  and
 and  : the role of the secondary is to determine
   the crack front/tip).
   note:
      All tools listed below need the package qhull installed on your
      system. This package is widely available. It computes convex hull and
      delaunay triangulations in arbitrary dimension.
 : the role of the secondary is to determine
   the crack front/tip).
   note:
      All tools listed below need the package qhull installed on your
      system. This package is widely available. It computes convex hull and
      delaunay triangulations in arbitrary dimension.
LS = gf_levelset(mesh m, int d[, string 'ws'| string f1[, string f2 | string 'ws']])
General constructor for levelset objects.
The level-set object is represented by a primary level-set and optionally
   a secondary level-set used to represent fractures (if p(x) is the primary
   level-set function and s(x) is the secondary level-set, the crack is
   defined by  and
 and  : the role of the secondary is to determine
   the crack front/tip).
   note:
      All tools listed below need the package qhull installed on your
      system. This package is widely available. It computes convex hull and
      delaunay triangulations in arbitrary dimension.
 : the role of the secondary is to determine
   the crack front/tip).
   note:
      All tools listed below need the package qhull installed on your
      system. This package is widely available. It computes convex hull and
      delaunay triangulations in arbitrary dimension.
LS = gf_levelset(mesh m, int d[, string 'ws'| string f1[, string f2 | string 'ws']])
Create a levelset object on a mesh represented by a primary function
      (and optional secondary function, both) defined on a lagrange mesh_fem of
      degree d.
      If ws (with secondary) is set; this levelset is represented by a
      primary function and a secondary function. If f1 is set; the primary
      function is defined by that expression (with the syntax of the high
      generic assembly language). If f2 is set; this levelset
      is represented by a primary function and a secondary function defined
      by these expressions.
Y. Collette