1. Commands understanding
   1. Natural language acquisition
      1. Simbol grounding
         1. Language recognition
            1. Words recognition
2. Action planning and execution
   1. Action result prediction
      1. Basic action recognition
      2. Environment understanding
         1. Environment recognition
            1. Object recognition
            2. Location recognition
         2. Instructor intension reading
            1. Mind theory
            2. Instructor recognition
            3. Joint attention
   2. Execution control