Exclude Template

The Exclude template has the form:

[item or condition] excludes [item or condition]

The exclude constraint is mutual. For example, if Item A is present in the solution, Item B cannot be present. Conversely, if Item B is present, Item A cannot be present.

The excludes constraint is functionally equivalent to a Boolean ! (A AND B), that is, a NAND operator. In the following table, a T (true) means the item is present in the solution. An F (false) means it is not present or is excluded.

A	B	A AND B	! (A AND B)
T	F	False	True
F	T	False	True
F	F	False	True
T	T	True	False

The truth table shows that an exclude constraint is always true except when both operands are present in the solution.

Use an exclude constraint to:

• Prevent technical configuration errors. For example, a computer operating system or software application may be incompatible with certain microprocessors.

• Prevent configurations that are undesirable or ineffective. For example, in a financial model, an exclude constraint could prevent adding a low quality bond fund to a retirement portfolio.