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**Index**
**Contents**

This structure contains the following information (see chapter 1):

- the
*nature*of the element; - the list of the
*vertices*of the element; - the element
*connectivity*and*topology*; - the
*number*and list of the nodes; - the
*coordinates*of the vertices; - the
*physical attributes*of the element:- a
*sub-domain number*number and*references*.

- a

The MODULEF code stores this information in a ** NOPO** type data structure, constituting the natural interface
between the different mesh modules.

** Remark:**

- The sub-domains : The notion of materials is refined to distinguish between two identical media subject to different conditions: as many sub-domain numbers are assigned as required to make this distinction;
- The references : This attribute has two functions:
- to characterize the items (edges, faces and points) with respect to a boundary condition type treatment (loads, prescribed values, etc.)
- to describe a boundary from a geometric point of view: i.e. to associate a curve or surface equation to a portion of the boundary.

As many reference numbers are assigned as required in order to incorporate the entire set of descriptions.