{
  "Comment": "https://states-language.net/spec.html#parameters",
  "StartAt": "X",
  "States": {
    "X": {
      "Type": "Task",
      "Resource": "${lambdaArn}",
      "Parameters": {
        "flagged": true,
        "parts": {
          "first.$": "$.vals[0]",
          "last3.$": "$.vals[3:]"
        }
      },
      "End": true
    }
  }
}