In Prolog a variable is a placeholder to be filled in, sooner or later, but only once. That is, a logical variable can only be assigned a value at most one time.

Note: On backtracking, such assignments can be undone and ready for the next assignment.

For information on the Myers Briggs Personality Types, see Myers-Briggs personality profiles.

The following are generalizations but appear to have some basic truth in them.

Sensing types like to have everything defined as one goes so that everything is known.

Sensing types often do not handle new information well that contradicts what they have previously learned.

Sensing types like call by value parameter passing as everything is decided at the call, in an eager manner.

Intuitive types do not need all the required information as one goes. Placeholders are used (in the brain) for concepts, definitions, etc., to be filled in later.

Intuitive types are better prepared to adjust views and ideas based on new information that contradicts what they have previously learned.

Intuitive types are not bothered by a Prolog call by pattern matching whereby placeholders are passed with values to be filled in later, with the minimum bindings necessary (unification) based on later constraints encountered.