How to write PDDL Domain and Problem file?

Question

I am trying to do some planing project by using PDDL. I want to do from some natural text. Like:

1. Take the knife from left to right hand.
2. Cut the apple.
3. Wash knife.

I am confused abut the predicates and action. how to defined the predicates?

Answer 1

Predicates are the things that can be true or false in a state of the environment. E.g., (holding ?hand ?item).

Actions would be the things that change the world. E.g., take, cut, wash.