The declaration of a fact must be set:

a) His name is represented by a sequence of characters, possibly containing spaces. Note: two facts in a base must not have the same name.

b) Its type which can be one of the following: Boolean, symbol, and real.

1. The Boolean Type: a fact of Boolean type possible values: true or false.

Note: starting with version 1.3, we can associate a fact of type Boolean with variables.

2. The symbol type: A set of values determined by the expert when it constitutes the knowledge base.

Example: a symbolic Fact [desired availability] has three possible values:

maximum, medium, unimportance.

3. The real type: the possible values of a fact real type also called as real fact are real numbers.

See also rule creation.