Assertion: obstacle | /r/Synonym | layering
Facets:
Source sentences:
text: The walk-through is critical for success because the course's path takes various turns, even U-turns or 270° turns, can cross back on itself, can use the same obstacle more than once, can have two obstacles so close to each other that the dog and handler must be able to clearly discriminate which to take, and can be arranged so that the handler must work with obstacles between himself and the dog, called layering, or at a great distance from the dog.