Method Additions

+SomeObject :: asserta(+SomeMethod)

+SomeObject :: assertz(+SomeMethod)

+SomeObject :: assert(+SomeMethod)

Asserts SomeMethod in SomeObject with normal Prolog semantics.

Add some facts to vehicle and truck with initial value equal to [].

     | ?- vehicle :: assert(fuel_level([])),
          vehicle :: assert(oil_level([])),
          vehicle :: assert(location([])),
          truck :: assert(capacity([])),
          truck :: assert(total_weight([])).