I have some doubts about the operator: -op in Prolog, because I can not handle it. My exercise is focused on creating a predicate that from a list attribute-value, whose format is [a1 => v1, a2 => v2, ..., aN => vN], get the value of a attribute that is requested.
Example:? - value (shape, [color => blue, shape = spherical, weight => light, material = > plastic], X). X = spherical.
To do this, we suggest defining the operator = > in the logical base.