curl --request GET \
  --url 'https://api.nsr.stateset.com/api/v1/beliefs/{proposition}' \
  --header 'X-API-Key: YOUR_API_KEY'

{
  "belief_interval": [
    {}
  ],
  "confidence": 1,
  "is_certain": true,
  "is_rejected": true,
  "proposition": "string",
  "uncertainty": 1
}