Calculate Fixture

	 * It doesn't mark some header names with "()". Instead, it separates the given columns (to the left) and calculated columns (to the right) by an empty column.
	 * It allows ExtendedCamelCase in the names in the header row

Calculatesum
a	b		+
1	2		3
-3	3		0

The first two columns are given; the third is calculated. The underlying calculated method is plus().