We can also use nested tables to directly express domain objects. Again, let's use a very simple example. We want to define the addition of two vectors:
!**< test
!define vector1 (|''x''|5|
|''y''|7|
)
!define vector2 (|''x''|10|''y''|20|
)
!define vector3 (|''x''|15|
|''y''|27|
)
**!

!|fitlibrary.eg.VectorAddition|

|'''check'''|''add''|${vector1}|''to''|${vector2}|${vector3}|

Notice that the domain objects are defined as property-value pairs. There can be one or more pairs in a row.

Now the method ''addTo()'' is defined as follows:
----{{{	public Vector addTo(Vector v1, Vector v2) {
		return v1.add(v2);
	}
}}}----
Here's the steps that happen automatically:
 * Before the method is called, the first two nested tables need to be converted into a ''Vector''. Let's just discuss the first one. As there is an inner table for the object, ''!-FitLibrary-!'' automatically creates an object of class ''Vector'' and uses a ''!-DomainObjectSetUpFixture-!'' to set the properties appropriately from the table.
 * The method ''addTo()'' is called.
 * The result of the method is checked against the third nested table. As the result type is an object (of type ''Vector'') and there's a nested table, ''!-FitLibrary-!'' automatically uses a ''!-DomainObjectCheckFixture-!'' to check that the properties in the table and the object correspond.
Here's all the Java code:
----{{{public class VectorAddition extends DoFixture {
	public Vector addTo(Vector v1, Vector v2) {
		return v1.add(v2);
	}
	public static class Vector {
		private int x, y;

		public Vector() {
			//
		}
		public Vector(int x, int y) {
			setX(x);
			setY(y);
		}
		public Vector add(Vector v2) {
			return new Vector(x+v2.getX(),y+v2.getY());
		}
		public int getX() {
			return x;
		}
		public void setX(int x) {
			this.x = x;
		}
		public int getY() {
			return y;
		}
		public void setY(int y) {
			this.y = y;
		}
	}
}
}}}----
Notice that:
 * class ''Vector'' needs a nullary constructor (ie, it's a Java bean)
 * The only fixture mentioned is the first one
 * Much of the work happens automatically
Let's now consider GeneralNesting.