gmsh: points to define mesh sizes in surfaces.

Point(1) = {0, 0, 0, 0.1};
Point(2) = {1, 0, 0, 0.1};
Point(3) = {0, 1, 0, 0.1};
Point(4) = {1, 1, 0, 0.1};
Point(5) = {0.5, 0.1, 0, 0.005};
Line(1) = {3, 4};
Line(2) = {4, 2};
Line(3) = {2, 1};
Line(4) = {1, 3};
Line Loop(5) = {1, 2, 3, 4};
Plane Surface(6) = {5};
Point{5} In Surface{6};
~
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