<set>.CURRENTMEMBER
Gives the current tuple in set. The concept of “currency” occurs in functions such as GENERATE where the semantics include some form of iteration through tuples of a set.
<set>[.ITEM](<string_expression> [, <string_expression>...] | <index>)
Returns a tuple from set. The <string_expression> [, <string_expression>...] specifies which tuple to retrieve. The index value specifies the position of the tuple in set. The numbering of the tuples is zero-based.