#voussoir  wedge-shaped stone building block used in constructing an arch or vault
  supertype:  building_block.building_material__buildingblock  a block of material used in construction work
  part of:  arch  (architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it
     part of:  aqueduct  a conduit that resembles a bridge but carries water over a valley
     part of:  arcade.structure__colonnade  a structure composed of a series of arches supported by columns
     part of:  bridge__span  a structure that allows people or vehicles to cross an obstacle such as a river or canal or railway etc.
        part of:  transportation_system__transportation__transit  facility consisting of the roads and equipment necessary for the movement of passengers or goods
           part of:  infrastructure__base  the stock of basic facilities and capital equipment needed for the functioning of a country or area; "the industrial base of Japan"

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