#proscenium_arch  the arch over the opening in the proscenium wall
  supertype:  arch  (architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it
  part of:  proscenium_wall__proscenium  the wall that separates the stage from the auditorium in a modern theater
     part of:  theater_stage__theaterstage__theatre_stage__theatrestage  a stage in a theater on which actors can perform
        part of:  theater__house  a building where theatrical performances or motion-picture shows can be presented; "the house was full"

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