52 lines
847 B
Markdown
52 lines
847 B
Markdown
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# Collatz Conjecture
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Collatz Conjecture (Snowflake / `3n+1`) done in the GHC Type System.
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## Running
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in `ghci` load the file:
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```
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:load collatz.hs
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```
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and run with the following:
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```
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:t solution (nil :: X)
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```
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where `X` is the church encoding using `S n` and `Z`, ie
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`(S (S (S Z)))` is the number `3`
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## Example
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```
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*Main> :t solution (nil :: (S (S (S Z))))
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solution (nil :: (S (S (S Z))))
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:: Cons
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(S (S (S Z)))
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(Cons
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(S (S (S (S (S (S (S (S (S (S Z))))))))))
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(Cons
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(S (S (S (S (S Z)))))
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(Cons
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(S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S Z))))))))))))))))
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(Cons
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(S (S (S (S (S (S (S (S Z))))))))
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(Cons
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(S (S (S (S Z))))
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(Cons
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(S (S Z))
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(Cons
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(S Z)
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Nil)))))))
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```
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which translates to the following list:
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```
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[ 3 10 5 16 8 4 2 1 ]
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```
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