[
  {"op": "doc", "text": "spread pattern variant 2 for prefix ambiguity probe"},
  {"op": "input", "role": "price"},
  {"op": "add", "type": "SMA", "name": "fast"},
  {"op": "add", "type": "SMA", "name": "slow"},
  {"op": "feed", "role": "price", "into": ["fast.series", "slow.series"]},
  {"op": "add", "type": "Sub", "name": "sub"},
  {"op": "connect", "from": "fast.value", "to": "sub.lhs"},
  {"op": "connect", "from": "slow.value", "to": "sub.rhs"},
  {"op": "expose", "from": "sub.value", "as": "spread"}
]