+ <center>
+ \image html image122.png
+ <em>"Edit Hypothesis" button</em>
+ </center>
+
+ Most 2D and 3D algorithms can work without hypotheses using default meshing parameters. Some algorithms do not require any hypotheses. After selection of an algorithm "Hypothesis" field of
+ the dialog can contain:
+ <ul>
+ <li> <em>\<Default\></em> if the algorithm can work using default
+ parameters.</li>
+ <li> <em>\<None\></em> if the algorithm requires a hypothesis defining
+ its parameters.</li>
+ <li> If the algorithm does not use hypotheses, this field is grayed.</li>
+ </ul>
+ After selection of an algorithm <b>Add. Hypothesis</b> field can contain:
+ <ul>
+ <li> <em>\<None\></em> if the algorithm can be tuned
+ using an additional hypothesis.</li>
+ <li> If the algorithm does not use additional hypotheses, this field is grayed.</li>
+ </ul>
+
+ Proceed in the same way with 2D and 1D Algorithms and Hypotheses that
+ will be used to mesh faces and edges of your geometry. (Note
+ that any object has edges, even if their existence is not
+ apparent, for example, a sphere has 4 edges). Note that the
+ choice of hypotheses and lower dimension algorithms depends on
+ the higher dimension algorithm.
+
+ Some algorithms generate mesh of several dimensions, while others
+ produce mesh of only one dimension. In the latter case there must
+ be one Algorithm and zero or several
+ Hypotheses for each dimension of your object, otherwise you will
+ not get any mesh at all. Of course, if you wish to mesh a face,
+ which is a 2D object, you do not need to define a 3D Algorithm and
+ Hypotheses.
+
+ In the <b>Object Browser</b> the structure of the new mesh will be
+ displayed as follows:
+
+ <center>
+ \image html image88.jpg
+ </center>
+
+ It contains:
+ <ul>
+ <li>a reference to the geometrical object on the basis of
+ which the mesh has been constructed;</li>
+ <li><b>Applied hypotheses</b> folder containing the references
+ to the hypotheses applied at the construction of the mesh;</li>
+ <li><b>Applied algorithms</b> folder containing the references
+ to the algorithms applied at the construction of the mesh.</li>
+ </ul>
+
+ There is an alternative way to assign Algorithms and Hypotheses by
+ clicking <b>Assign a set of hypotheses</b> button and selecting among
+ pre-defined sets of hypotheses. In addition to the standard
+ sets of hypotheses, it is possible to create custom sets by editing
+ CustomMeshers.xml file located in the home directory. CustomMeshers.xml
+ file must describe sets of hypotheses in the
+ same way as ${SMESH_ROOT_DIR}/share/salome/resources/smesh/StdMeshers.xml
+ file does (sets of hypotheses are enclosed between <hypotheses-set-group>
+ tags).
+
+ \image html hypo_sets.png
+ List of sets of hypotheses. Tag <em>[custom]</em> is
+ automatically added to the sets defined by the user
+ </li>
+</ol>
+
+Consider trying a sample script for construction of a mesh from our
+\ref tui_creating_meshes_page "TUI Scripts" section.
+
+\anchor evaluate_anchor
+<h2>Evaluating mesh size</h2>
+
+After the mesh object is created and all hypotheses are assigned and
+before \ref compute_anchor "Compute" operation, it is possible to
+calculate the eventual mesh size. For this, select the mesh in
+the <b>Object Browser</b> and from the \b Mesh menu select \b
+Evaluate. The result of evaluation will be displayed in the following
+information box:
+
+\image html mesh_evaluation_succeed.png
+
+\anchor preview_anchor
+<h2>Previewing the mesh</h2>
+
+Before \ref compute_anchor "the mesh computation", it is also possible
+to see the mesh preview.
+
+For this, select the mesh in the Object Browser. From the \b Mesh menu
+select \b Preview or click "Preview" button in the toolbar or activate
+"Preview" item from the pop-up menu.
+
+<center>
+\image html mesh_precompute.png
+<em>"Preview" button</em>
+</center>
+
+Select <b>1D mesh</b> or <b>2D mesh</b> preview mode in the Preview dialog.
+
+\image html preview_mesh_1D.png "1D mesh preview shows nodes computed on geometry edges"
+<br>
+\image html preview_mesh_2D.png "2D mesh preview shows edge mesh elements, computed on geometry faces"
+
+<b>Compute</b> button computes the whole mesh.
+
+When the Preview dialog is closed, the question about the storage of temporarily
+created mesh elements appears:
+
+\image html preview_tmp_data.png
+
+These elements can be kept in the mesh.
+
+
+\anchor submesh_order_anchor
+<h2>Changing sub-mesh priority</h2>
+
+If the mesh contains concurrent \ref constructing_submeshes_page "sub-meshes",
+it is possible to change the priority of their computation, i.e. to
+change the priority of applying algorithms to the shared sub-shapes of
+the Mesh shape.
+
+<em>To change submesh priority:</em>
+
+Choose "Change submesh priority" from the Mesh menu or a pop-up
+menu. The opened dialog shows a list of submeshes in the order of
+their priority.
+
+There is an example of submesh order modifications taking a Mesh created on a Box
+shape. The main Mesh object:
+<ul>
+ <li><i>1D</i> <b>Wire discretisation</b> with <b>Number of Segments</b>=20</li>
+ <li><i>2D</i> <b>Triangle (Mefisto)</b> with Hypothesis<b>Max Element Area</b>
+ </li>
+</ul>
+The first submesh object <b>Submesh_1</b> created on <b>Face_1</b> is:
+<ul>
+ <li><i>1D</i> <b>Wire discretisation</b> with <b>Number of Segments</b>=4</li>
+ <li><i>2D</i> <b>Triangle (Mefisto)</b> with Hypothesis <b>MaxElementArea</b>=1200</li>
+</ul>
+The second submesh object <b>Submesh_2</b> created on <b>Face_2</b> is:
