List/Table Comprehension Expression
A list comprehension expression evaluates to a List of Tuples. The tuple elements are defined by the expressions in the report part, one tuple for each variable combination of the from part that fulfills the optional boolean predicate in the with part. When no with part is given, all combinations result in a tuple.
Optionally, tuple elements can be named via the as keyword together with string expression. In this case, the result is a Table.
When there is only one expression in the report part, the resulting List will not contain unary Tuples, but simply the values.