Noteworthy and corner cases

Intersection operator

The intersection operator is a single space . This will need to remark this in the paper and make sure it's correct in the grammar, maybe look at a Python/makefile grammar for inspiration

Union operator

The union operator is not a real union operator. COUNT(A2,A2) == 2, COUNT(A2) == 1.

The union operator is a comma ,, but is not accepted by every function. For functions with only 1 argument, the arguments are treated as a union.

SUM(A1,A2) == SUM((A1,A2))
SMALL(A1,A2) != SMALL((A1,A2),1)