x_3 y_3 z_3 tolerance

This data item defines a quadrilateral in space.
Other data items can check if nodes are located on this geometry.
The coordinates of the corner points are *x_0 y_0 z_0* etc..
In 2D, only *x_0*, *y_0* etc. should be specified etc..
The points of the quadrilateral should be specified in the correct order;
the order is clearified in the example below.

All **node** within a distance *tolerance* are considered
to be part of the quadrilateral (this gives a brick with thickness
).
Internally in TOCHNOG, the quadrilateral is divided into two
**geometry_triangle**s, which is only approximately true if the
quadrilateral is twisted. Example

...number_of_space_dimensions 2

...geometry_quadrilateral 0 0. 0. 1. 0. 0. 1. 1. 1.

...

Notice the order in which the points are to be specified.