#gas_system__gassystem  facility (plant and equipment) for providing natural-gas service
  supertype:  #installation__facility  a building or place that provides a particular service or is used for a particular industry; "the assembly plant is an enormous facility"
  part:  #gas_main
  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"

No statement uses or specializes #gas_system; click here to add one.