The construct, Index i := seqExpr defines an index local to the definition in which it is used. The expression seqExpr may be a sequence, literal list, or other expression that generates an unindexed array, as used to define a global index. For example:
Variable PowersOf2 Definition: Index J := 0..5; 2^J
The new Variable PowersOf2 is an array of powers of two, indexed by the local index J, with values from 0 to 5:
The dot operator let's you refer to a local index of an array.
Index I := seqExpr Do bodyExpr
Index I := seqExpr; expr; expr; ...
To control the index name, separate from the local variable name:
Index I / nameExpr := seqExpr Do bodyExpr