You are an AI assistant tasked with analyzing a passage of text to insert retrieval tokens and identify Prefix-intent (PI) and Key Factual Information (KFI). A Prefix-Intent (PI) should be a piece of text that should precede factual information, it must not be only 1 or 2 words. Key Factual Information (KFI) should be meaningful and include important details.

Your goal is to insert a  <|retrieval|> token after it is clear what the intent of the text is (e.g., "The president of the USA is"), but  before the key factual information is stated (e.g., "Joe Biden"). Whenever there is a <|retrieval|> token, we will retrieve the key factual information.

Here is the passage you will be working with:

<passage>
List of musical instruments by Hornbostel–Sachs number: 421 Edge-blown aerophones is one of the categories of musical instruments found in the Hornbostel–Sachs system of musical instrument classification. In order to produce sound with these aerophones, the player makes a ribbon-shaped flow of air with their lips (421.1), or their breath is directed through a duct against an edge (421.2). 421.1 Flutes without duct – The player creates a ribbon-shaped stream of air with their lips. 421.11 End-blown flutes – The player blows against the sharp rim at the upper open end of a tube. 421.111 Individual end-blown flutes 421.111.1 Open single end-blown flutes – The lower end of the flute is open. 421.111.11 Without fingerholes. 421.111.12 With fingerholes. Anasazi flute Danso Kaval Ney Nose flute Palendag Quena Shakuhachi Sring Suling Tungso Washint Xiao 421.111.2 Stopped single end-blown flutes – The lower end of the flute is closed. 421.111.21 Without fingerholes. 421.111.22 With fingerholes. 421.112 Sets of end-blown flutes or panpipes – Several end-blown flutes of different pitch are combined to form a single instrument. Diple 421.112.1 Open panpipes. 421.112.11 Open (raft) panpipes – The pipes are tied together in the form of a board, or they are made by drilling tubes *in a board. 421.112.12 Open bundle (pan-) pipes – The pipes are tied together in a round bundle. 421.112.2 Stopped panpipes Pan flute Siku 421.112.3 Mixed open and stopped panpipes. 421.12 Side-blown flutes – The player blows against the sharp rim of a hole in the side of the tube. 421.121 (Single) side-blown flutes. 421.121.1 Open side-blown flutes. 421.121.11 Without fingerholes. 421.121.12 With fingerholes Bansuri Chi Daegeum Dangjeok Dizi Fife Gakubue Hotchiku Kagurabue Junggeum Komabue Koudi Minteki Nohkan Piccolo Ryuteki Sáo Seiteki shinobue Sogeum Western concert flutes Alto flute Bass flute Contra-alto flute Contrabass flute Double contrabass flute Hyperbass flute 421.121.2 Partly stopped side-blown flutes - The lower end of the tube is a natural node of the pipe pierced by a small hole. 421.121.3 Stopped side-blown flutes. 421.121.31 Without fingerholes. 421.121.311 With fixed stopped lower end - (Apparently non-existent). 421.121.312 With adjustable stopped lower end 421.121.32 With fingerholes. 421.122 Sets of side-blown flutes. 421.122.1 Sets of open side-blown flutes. 421.122.2 Sets of stopped side-blown flutes. 421.13 Vessel flutes (without distinct beak) The body of the pipe is not tubular but vessel-shaped. 421.2 Flutes with duct or duct flutes - A narrow duct directs the air-stream against the sharp edge of a lateral orifice 421.21 Flutes with external duct - The duct is outside the wall of the flute; this group includes flutes with the duct chamfered in the wall under a ring-like sleeve and other similar arrangements. 421.211 (Single) flutes with external duct. 421.211.1 Open flutes with external duct. 421.211.11 Without fingerholes. 421.211.12 With fingerholes. Native American flute 421.211.2 Partly stopped flutes with external duct. 421.211.3 Stopped flutes with external duct. Boatswain's call 421.212 Sets of flute with external duct. 421.22 Flutes with internal duct - The duct is inside the tube. This group includes flutes with the duct formed by an internal baffle (natural node, bock of resin) and an exterior tied-on cover (cane, wood, hide). 421.221 (Single) flutes with internal duct. 421.221.1 Open flutes with internal duct. 421.221.11 Without fingerholes. 421.221.12 With fingerholes. Atenben Flageolet Fujara Khloy Khlui Recorder Tin whistle Tonette 421.221.2 Partly stopped flute with internal duct. 421.221.3 Stopped flutes with internal duct. whistle 421.221.31 Without fingerholes. 421.221.311 With fixed stopped lower end. 421.221.312 With adjustable stopped lower end. Slide whistle 421.221.4 Vessel flutes with duct. 421.221.41 Without fingerholes 421.221.42 With fingerholes Gemshorn Ocarina 421.222 Sets of flutes with internal duct. 421.222.1 Sets of
</passage>

Follow these steps to complete the task:

1. Inserting retrieval tokens:
   a. Read through the text carefully.
   b. Identify potential Prefix-Intent (PI) sections that consist of a single intent and could serve as a search query. You must not modify the prefix intent and it MUST be part verbatim in the passage. It cannot be single or only a few words.
   c. For each identified PI, evaluate if the following sentence/subsentece that could serve as Key Factual Information (KFI).
   d. Insert <|retrieval|> tokens into the text AFTER the Prefix Intent (PI) and BEFORE key factual information is stated (KFI).
   e. Key Factual information should not intersect with Prefix Intent.

2. Identifying Prefix-Intent (PI) and Key Factual Information (KFI):
   a. For each <|retrieval|> token you've inserted, identify the preceding text as the Prefix-Intent (PI).
   b. Identify the following text, up to the next PI, as the Key Factual Information (KFI).
   c. Ensure that both PI and FI are short subsentences or phrases but not 1 or 2 words.

3. Insert <|start-PI|>,<|end-PI|>, <|start-KFI|>, <|end-KFI|>.
   a. For each identified Prefix Intent (PI), add a start and end special tokens (<|start-PI|>,<|end-PI|>) to quickly identify them.
   b. Do the same for the Key Factual Information (KFI) (<|start-KFI|>, <|end-KFI|>)
   c. Ensure that the very first PI in the passage is preceded by <|start-PI|>.
   d. Double-check that every PI and KFI is properly enclosed in these tags.

4. Describing ideal retrieved information:
   a. Given the Prefix-Intent (PI) and Key Factual Information (KFI), imagine an ideal retriever and enormous corpus. 
   b. Using the retriever and corpus, imagine that you can retrieve information given the Prefix-Intent.  
   c. Describe how that content should look like so it helps generating the Key Factual Information (KFI)


5. Reformulate the Prefix Intent if necessary: Reformulate it to not be impersonal. This means that if the subject it is not identified (e.g. it, he, she) you need to add the appropriate subject so the prefix-intent can be understood by itself. The subject should be changed from the previous information in the passage. Reformulated Prefix should not add any extra information or intent that is not mentioned in the original Prefix Intent.


6. Output format:
   For each pair of Prefix-Intent (PI) and Key Factual Information (KFI) you identify, provide the following output separating each example in a JSON list output. Ensure that it is actually a JSON.

   - Prefix_intent: [Write the Prefix Intent here]
   - Prefix_reformulated: [Write the Prefix Intent reformulated]
   - Key_Factual_Information: [Write the Key Factual Information here]
   - Verification: [Confirm that the KFI can be directly derived from the PI given a strictly connected context]
   - Ideal_Knowledge: [Describe how the ideal retrieved content should look to generate the KFI]
   - Explanation: [Briefly explain how the PI and KFI connect and why you chose to insert the <|retrieval|> token in that position]


7. Final step:
   After you have completed the analysis and provided outputs for all identified PI-KFI pairs, present the original passage with the <|retrieval|> tokens inserted in their appropriate positions

Here's an example of the expected output format:

Passage: Girmal Falls General This waterfall extends to a height of up to 100 feet, making it the highest waterfall of Gujarat. The picturesque beauty of this site makes it popular among visitors and people of the region alike. The water swiftly falls from a great height, creating a fog like condition that’s eye catching. The government of this state is working on many projects to make this place an ideal picnic spot and a tourist attraction. The fall comes to its best form at the time of monsoon and provides an immensely striking appearance. Some of the best natural features of Gujarat can be explored in this place. This place is a nice and refreshing retreat for any traveler.

```json
{ "results" : [
  {
    "Prefix_intent": "Girmal Falls General This waterfall extends to a height of up to",
    "Prefix_reformulated": "What is the height of Girmal Falls?",
    "Key_Factual_Information": "100 feet, making it the highest waterfall of Gujarat",
    "Verification": "The KFI directly provides the height information requested in the PI.",
    "Ideal_Knowledge": "A list of waterfalls in Gujarat, India, with their heights and rankings, specifically mentioning Girmal Falls as the highest at 100 feet.",
    "Explanation": "The PI introduces Girmal Falls and sets up a query about its height, while the KFI provides the specific measurement and its significance. The <|retrieval|> token is inserted to indicate where additional information might be needed to support the factual statement."
  },
  {
    "Prefix_intent": "The water swiftly falls from a great height, creating",
    "Prefix_reformulated": "What does the water falling from Girmal Falls create?",
    "Key_Factual_Information": "a fog like condition that's eye catching",
    "Verification": "The KFI directly describes the effect created by the falling water, as prompted by the PI.",
    "Ideal_Knowledge": "Detailed descriptions of the visual effects created by high waterfalls, including the formation of mist or fog-like conditions due to water droplets in the air.",
    "Explanation": "The PI describes the water falling and sets up a query about its effect, while the KFI provides the specific visual phenomenon created. The <|retrieval|> token is inserted to indicate where additional information might be needed to support the description."
  },
  {
    "Prefix_intent": "The fall comes to its best form at the time of",
    "Prefix_reformulated": "When does Girmal Falls come to its best form?",
    "Key_Factual_Information": "monsoon and provides an immensely striking appearance",
    "Verification": "The KFI directly answers when the waterfall is at its best and describes its appearance, as prompted by the PI.",
    "Ideal_Knowledge": "Information on the seasonal variations of Girmal Falls, highlighting the monsoon season's impact on water flow and visual appeal.",
    "Explanation": "The PI sets up a query about the best time to view the falls, and the KFI provides the specific season and describes the appearance. The <|retrieval|> token is inserted to indicate where additional information about seasonal changes might be needed."
  }],
"Updated_Passage":"<|start-PI|> Girmal Falls General This waterfall extends to a height of up to <|end-PI|> <|retrieval|> <|start-KFI|> 100 feet, making it the highest waterfall of Gujarat <|end-KFI|>. The picturesque beauty of this site makes it popular among visitors and people of the region alike. <|start-PI|> The water swiftly falls from a great height, creating <|end-PI|> <|retrieval|> <|start-KFI|> a fog like condition that’s eye catching <|end-KFI|>. The government of this state is working on many projects to make this place an ideal picnic spot and a tourist attraction. <|start-PI|> The fall comes to its best form at the time of <|end-PI|> <|retrieval|> <|start-KFI|> monsoon and provides an immensely striking appearance <|end-KFI|>. Some of the best natural features of Gujarat can be explored in this place. This place is a nice and refreshing retreat for any traveler."
}

```
8. Final check:
  a. Review the Updated_Passage to ensure all PIs and KFIs are properly tagged.
  b. Verify that the first PI in the passage starts with <|start-PI|>.
  c. Make sure there are no missing or misplaced tags.
 
Remember to analyze the entire passage, identify all relevant PI-KFI pairs, and provide the output for each pair as specified. After completing the analysis, present the original passage with the <|retrieval|> tokens inserted in their appropriate positions as part of a new key in the JSON file. Only Ouput the JSON File.