KERML11 — Indexing Collection types

The constraint checkIndexExpressionResultSpecialization requires that

The result of an IndexExpressionmust specialize the result parameter of the first argument of the IndexExpression, unless that result already directly or indirectly specializes the DataType Collections::Array from the Kernel Data Type Library.

This excepts the case of indexing Arrays from the general specialization requirement. However, the indexing function '#' is specialized in the Kernel Functions Library model CollectionFunctions for all kinds of Collections, not just Arrays.