# Card order can influence the order of evaluation sets

When an evaluation set is selected, card object names are ordered by their position in the map: card 1 before card 2, and so on. The card order for a map can affect the order of output results.

For example, suppose you want to evaluate the following map rule.

``NumberSet ( s ) = B:Card2 + A:Card1``

In this example, an evaluation set for this rule consists of one value for B and one value for A. One evaluation set produces one NumberSet.

As an example, here there are three As and three Bs in the data:
A Values B Values
1 3
2 2
3 1

There are nine evaluation sets. The order of the cards might affect the order of the evaluation sets.

If Card 1 is the first card, you get the following results:
Evaluation # A B Result
1 1 3 4
2 2 3 5
3 3 3 6
4 1 2 3
5 2 2 4
6 3 2 5
7 1 1 2
8 2 1 3
9 3 1 4
If Card 2 is the first card, you get the following results:
Evaluation # B A Result
1 3 1 4
2 2 1 3
3 1 1 2
4 3 2 5
5 2 2 4
6 1 2 3
7 3 3 6
8 2 3 5
9 1 3 4

If both A and B are contained in the same card object, evaluation sets are selected based on the order A and B appear in the rule. Leftmost objects are selected first. If you change the rule to this:

``NumberSet ( s ) = B:Card2 + A:Card2``

the same results are produced as when card 2 is the first card.