diff --git a/src/MiniDocs/Array.extension.st b/src/MiniDocs/Array.extension.st
new file mode 100644
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+++ b/src/MiniDocs/Array.extension.st
@@ -0,0 +1,28 @@
+Extension { #name : #Array }
+
+{ #category : #'*MiniDocs' }
+Array >> bagOfWordsFor: sentenceArray [
+	"An utility machine training little  algorithm.
+	Inspired by https://youtu.be/8qwowmiXANQ?t=1144.
+	This should be moved probably to [Polyglot](https://github.com/pharo-ai/Polyglot),
+	but the repository is pretty innactive (with commits 2 or more years old and no reponse to issues).
+	Meanwhile, it will be in MiniDocs.
+	
+	Given the sentence := #('hello' 'how' 'are' 'you')
+	and the  testVocabulary := #('hi' 'hello' 'I' 'you' 'bye' 'thank' 'you')
+	then 
+	
+	testVocabulary bagOfWordsFor: sentence.
+	
+	Should give: #(0 1 0 1 0 0 0)
+	"
+	| bagOfWords |
+	bagOfWords := Array new: self size.
+	bagOfWords doWithIndex: [:each :i | bagOfWords at: i put: 0 ].
+	sentenceArray do: [:token | |index|
+		index := self indexOf: token.
+		index > 0
+			ifTrue: [bagOfWords at: index put: 1] 
+	].
+	^ bagOfWords
+]