Static masses. Methods of finding elements. Actions on elements. The concept of a massif. A massif is a collection of information indexed by a unique identifier. The concept of an index variable indicates the type, name, and indexes of the massif. For example, a massif named 'a' consisting of elements of type 'type' is declared as follows: type a[length]; This correctly declares variables of type in the names a[0], a[1], ..., a[length-1] corresponding to the indexes