Write a function summarize$\_$letters that receives a string and returns a list of tuples containing the

unique letters and their frequencies in the string. Test your function and display each letter with its

frequency. Your function should ignore case sensitivity $($that is$,$a$$ and $$A$$ are the same$)$ and ignore

spaces and punctuation. When done, write a statement that says whether the string has all the letters of

the alphabet or not.

You can assume that there is no punctuation.

Input is $$Hello World$$

$[($h$,1),($e$,1),($l$,3)....]$

$(10$ points$)$ Program $2$: Counting Duplicate words

Write a script that uses a dictionary to determine and print the number of duplicate words in a

sentence. Treat uppercase and lowercase letters the same and assume there is no punctuation

in the sentence. Words with count larger than $1$ have duplicates.

Input: I love programming programming is fun

Output: $\{$I$$:$1,$love$$:$1,$programming$$:$2,$is$$:$1,$fun$$:$1\}$

$(5$ points$)$ Program $3$: Is a Sequence Sorted

$1.$ Search for the meaning of sequences in Python, and explain what is a sequence in

python?

$2.$ Create a function is ordered that receives a sequence and returns true if the elements

are in sorted order. Test your function with sorted and unsorted lists, tuples and strings.