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>
Timeline of Portland, Oregon The following is a timeline of the history of the city of Portland, Oregon, United States. 19th century 1850 – The Oregonian newspaper begins publication. 1851 Portland incorporated. Hugh O'Bryant becomes mayor. City's first general merchandise store opens, becoming Olds & King in 1878. Portland Public Schools is founded. 1855 – Lone Fir Cemetery established. 1857 – Aaron Meier's mercantile store, predecessor of Meier & Frank, in business. 1860 – Portland Gas Light Company in operation. 1864 – Library Association of Portland founded. 1866 – Oregon Herald newspaper begins publication. 1868 – Population: 6,717. 1871 – City Park established. 1872 – Portland Street Railway horsecars begin operating. 1875 – Good Samaritan Hospital founded. 1880 – Willamette University College of Medicine relocates to Portland. Portland Chamber of Commerce founded. 1881 – Unsightly beggar ordinance effected. 1882 – River View Cemetery established. 1883 – Northern Pacific Railway begins operating. 1885 – Web-Foot Cook Book published. 1886 – Oregon Staats Zeitung newspaper begins publication. 1887 – First Morrison Bridge, the first bridge across the Willamette River in Portland (and predecessor of the current Morrison Bridge), opens. 1888 – Portland Zoo established. 1890 Portland Hotel in business. Population: 46,385. 1891 The first Madison Street Bridge (predecessor of the Hawthorne Bridge) opens Albina and East Portland become part of city. Multnomah Athletic Club founded 1892 – Portland Art Association established. 1893 – Nov. 1: A streetcar plunges into the Willamette River from the Madison Street Bridge, the worst streetcar accident in the city's history 1895 – City Hall built. 1896 – Union Station opens. 1898 – Oregon Historical Society established. 1900 Quarterly of the Oregon Historical Society begins publication. Population: 90,426. 20th century 1900s–1940s 1901 – Columbia University and Hill Military Academy established. 1903 – Olmsted Portland park plan created. 1905 – June 1: Lewis and Clark Centennial Exposition opens. 1907 Portland Rose Festival begins. Portland Mill Strike of 1907 begins in March by lumber mill workers organized by the Industrial Workers of the World. The strike inspired unionization campaigns of bakers and sewer workers in Portland but had been called off by the end of April without winning its demands. 1908 – Reed College founded. 1909 – Audubon Society and Museum Art School founded. 1910 Hawthorne Bridge opens. Population: 207,214. 1912 – Steel Bridge and Globe Theatre open. 1913 – Broadway Bridge and Central Library building open. 1915 – Linnton and St. Johns become part of city. 1916 City Club of Portland established. Flatiron Building constructed. 1917 Interstate Bridge opens. Rose Test Garden established. Portland Public Auditorium opens. 1918- Portland is quarantined for a month, because of the Spanish Flu epidemic. 1919 – Louis' Oyster Bar in business. 1920 – Population: 258,288. 1920s – Pacific International Livestock Exposition facility built. 1921 – Blue Mouse Theatre in business. 1922 Hoyt Arboretum founded. KGW radio begins broadcasting. 1924 Portland Junior Symphony established. Founding of The Grotto (National Sanctuary of our Sorrowful Mother) 1925 – Sellwood Bridge opens. 1926 Second (and current) Burnside Bridge opens. Ross Island Bridge opens. Hollywood Theatre and Temple Beth Israel built. 1927 – Terminal Sales Building constructed. 1928 – Portland Publix Theater and Geller's Theatre open. 1930 – Swan Island Airport built. 1932 – Portland Art Museum building opens. 1938 – Lewis & Clark College active. 1940 – Portland Airport built. 1944 – Oregon Museum of History, Science, and Industry established. 1945 – Urban League branch and Portland Symphonic Choir founded. 1946 – Vanport Extension Center (college) and Portland Children's Museum established. 1948 May 30: Flood destroys the community of Vanport. Forest Park established. 1950s–1990s 1950 – Last
</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.