test_erfc = ->
  run_test [

    "erfc(a)",
    "erfc(a)",

    "erfc(0.0)",
    "1.0",

    "float(erfc(0))",
    "1.0",

    "erfc(0.0)",
    "1.0",

    "erfc(-0.0)",
    "1.0",

    "erfc(0)",
    "1",

    "erfc(-0)",
    "1",

    "float(erfc(1))",
    "0.157299...",
    
  ]