[
  {"op":"doc","text":"momentum: bias = sign(close - SMA(close,length)); length is the open IS-refit axis"},
  {"op":"source","role":"close","kind":"F64"},
  {"op":"add","type":"SMA","name":"sma"},
  {"op":"add","type":"Sub","name":"d"},
  {"op":"add","type":"Sign","name":"s"},
  {"op":"feed","role":"close","into":["sma.series","d.lhs"]},
  {"op":"connect","from":"sma.value","to":"d.rhs"},
  {"op":"connect","from":"d.value","to":"s.value"},
  {"op":"expose","from":"s.value","as":"bias"}
]