{
  /* as for the plus operator, the itemIDs must be sorted lexicographically and first word should come left */
  "item@basegame:112+item@basegame:116": { /* copper + tin -> bronze */
    "difficulty": 1.0,
    "product": [2, "item@basegame:176"]
  },
  "item@basegame:112+item@basegame:115": { /* copper + zinc -> brass */
    "difficulty": 1.0,
    "product": [2, "item@basegame:177"]
  },
  "item@basegame:117+item@basegame:118": { /* gold + silver -> electrum */
    "difficulty": 1.0,
    "product": [2, "item@basegame:178"]
  },
  "item@basegame:112+item@basegame:118": { /* copper + silver -> silver billon */
    "difficulty": 1.0,
    "product": [2, "item@basegame:179"]
  },
  "item@basegame:112+item@basegame:117": { /* copper + gold -> rose gold */
    "difficulty": 1.0,
    "product": [2, "item@basegame:180"]
  },
  "item@basegame:116+item@basegame:119": { /* tin + lead -> solder */
    "difficulty": 1.0,
    "product": [2, "item@basegame:181"]
  }
}