Printing object type 'object' in domains

[Roedhip]

The atomic_formula class' print_pddl() function specifically doesn't print the object's type if the type is just 'object', but when a predicate or function is being defined in the domain to apply to any object I am pretty sure I need to be print '?obj - object' instead of just '?obj'.

[m312z]

You don't need to include "- object" for an untyped parameter.

Types are preceded in the typed list by the hyphen "-" and each entity in the list is declared to be of the first type that follows it. If no type follows it in the list, then it is "object". You can mix typed and untyped (object) entities in the list as long as all untyped entities come after the types ones. For example, these should all be OK:

(a - type1 b - type1) ;; both a and b are type 1
(a b - type1) ;; both a and b are type 1
(a b c) ;; all a, b, and c are "object"
(a b - type1 c) ;; both a and b are type 1 and c is "object"
(a b - type1 c - object) ;; both a and b are type 1 and c is "object"

[Roedhip]

I am receiving errors from optic-cplex caused specifically by not having ' - object' printed in a function definition. Making the change back to having ' - object' allows optic-cplex to run with this domain.