{
  "required_concepts": [
    "singultus involuntary diaphragm or inspiratory muscle spasm",
    "rapid glottic closure produces the hic sound",
    "afferent vagal phrenic sympathetic inputs",
    "central brainstem spinal network not fully localized",
    "efferent phrenic and laryngeal response",
    "common transient triggers without guarantee",
    "evolutionary and fetal explanations only as hypotheses",
    "safe low-risk maneuvers with limited evidence",
    "no scare choking dangerous swallowing excessive water or fainting",
    "medications only under clinician supervision",
    "persistent over 48 hours and urgent symptom boundaries"
  ],
  "required_sources": [
    "Mayo Clinic or Cleveland Clinic in definition and persistence context",
    "medical review or Whitelaw/Straus in hiccup reflex arc context"
  ]
}