text: #!/usr/bin/env python
  import rospy
  from predicator_msgs.srv import *
  from predicator_msgs.msg import *
  
  p1 = PredicateStatement(predicate='link',params=['*','',''],num_params=1)
  p2 = PredicateStatement(predicate='up_from',params=['*','world','world'],num_params=2)
  p3 = PredicateStatement(predicate='in_front_of',params=['*','world','world'],num_params=2)
  
  srv = rospy.ServiceProxy('predicator/get_assignment',GetAssignment)
  and_srv = rospy.ServiceProxy('predicator/match_AND',Query)
  
  print srv(p1)
  print srv(p2)
  print srv(p3)
  
  print and_srv([p1,p2,p3])
  
  