For the input:

ri!sentence: "Appian is great and appian is powerful"

local!words: lower(split(trim(ri!sentence), " "))

Output:

{"appian", "is", "great", "and", "appian", "is", "powerful"}

Converting to lowercase ensures "Appian" and "appian" are treated as the same word.

a!forEach(

items: local!words,

expression: if(

length(wherecontains(fv!item, local!words)) > 1,

fv!item,

null

)

)

This loops through every word.

For each word:

wherecontains(fv!item, local!words)

returns the positions where that word appears.

Result:

{"appian", "is", null, null, "appian", "is", null}

reject(

fn!isnull,

...

)

Output:

{"appian", "is", "appian", "is"}

union(local!duplicatesList, local!duplicatesList)

union() removes duplicate values.

Output:

{"appian", "is"}

Final Output

{"appian", "is"}

For the sentence:

"Appian is great and appian is powerful"

the duplicate words are:

{"appian", "is"}