An important document handwritten by Alan Turing will be sold on April 13 in New York at the Bonhams sale. Detailing the foundations of computer science and mathematical notations, the document is expected to fetch at least seven figures.

The document, a modest notebook containing 56 pages, was first bought in the United Kingdom. Never been viewed by the public, the notes represent the only extensive handwritten manuscript from the Father of Computer Science in existence. According to evidence, the notes date back to 1942 from a time Turing was working to crack the German Enigma Code, shedding light into the genius' thought process while he was in Bletchley Park. They were included in papers left to Robin Gandy by Turing in his will.

Turing died in 1954 after committing suicide. His death was considered a result of hormone treatment he engaged in to "cure" his homosexuality, an alternative to going to prison. Gandy left the papers in 1977 at the King's College Archive Center. In Turing's old college, scholars were free to dissect his research using his own documents, except for one, the manuscript to be auctioned, which Gandy kept and used as a dream journal. It was only after Gandy's death that the manuscript resurfaced.

"Alan Turing was parsimonious with his words and everything from his pen has special value," said Andrew Hodges, a leading Turing scholar, adding the notebook particularly shines light on how Turing remained committed to working with pure mathematics despite being heavily involved in world events.

Cassandra Hatton, History of Science and Fine Books and Manuscripts senior specialist from Bonhams, said the manuscript is of notable value as it provides an in-depth perspective on Turing during one of his most critical achievements, a peek at the inner workings of the mind of one of the 20th century's greatest luminaries. To her, the manuscript was no doubt one of the most extraordinary items she had ever handled, and she's handled a lot, given her career.

The award-winning movie "The Imitation Game" was based off a book by Hodges called "Alan Turing: The Enigma" which starred Benedict Cumberbatch alongside Keira Knightley. Cumberbatch calls Turing a war hero for his work on the Enigma Code which brought an end to the Second World War. He also said that it was thrilling to hold a manuscript by Turing since the man had such an enormous impact on the lives of people living today.