When a variable appears in the
specification of a database,
the variable is .
Example:
likes(susie,Y)
For the
quantifier one may do two things:
a.Enter the value directly into the database
likes(george,Z)
becomes likes(george,wine)
b. Query the
interpreter
?- likes(george,Z) returns a value for Z if one exists
One interpretation:
‘Susie likes everyone’