What interests me more about maths is not its abstraction, which contributes to give this science a convoluted, not-for-everyone appearance. I don’t think the fact that “maths is everywhere” must necessarly attract students either, even though its practical applications are indeed innumerable and fascinating.

Above all, maths appears to me as a powerful instrument of self-knownledge, and a source of awareness of one’s own methods to face the outside world. Being a sort of “simplified” universe, with clear reference points and boundaries, maths can be of help with learning freedom and flexibility, with refining our creative potential, our concentration and simultaneous attention to small details and overall frame.

This perspective, I believe, should be taken into consideration even when strongly focused on results (i.e., exams and entry tests), since it makes the learning process more efficient and its effects durable.


If you need help with maths, don’t hesitate

Why dfnu?

A logo, an identity, a story

The logo “Dfnu” is actually a non-sense. The mathematical symbol usually refers to the partial derivative with respect to a tensor component.

It was “invented” during one of the many conversations I have with a dear friend of mine, while trying to discuss a topic we could hardly handle. We were having lunch at my place.

Is this possibly the most curious element? My home, and the street I live in, are somehow the “background scenario” of all my lectures, and they definitely (though accidentally) contribute to who I am and what I do.


Biography of an altrö-ego
Altrö, as his name suggests, has northern European origins. He grew up in Switzerland, nurturing his love for contemporary arts and baroque music.
My excellent cuisine and my digital piano – which now I can only play with his permission – transformed a quick detour in via Deffenu into a permanent change of address.
When he is not 100% concentrated on playing Jazz, he tries to help me in my mathematical explorations.


Matteo is an excellent professor. He manages to make the lessons fun and rigorous at the same time. He has infinite patience and will explain the same thing over and over from different perspectives until you truly understand. Additionally, he goes out of his way to help you make progress. He is always available to rescue you if you are stuck with an exercise or to recommend extra resources! And last but not least, he is very kind and reliable. I strongly recommend his lessons. Do not hesitate to contact him!
Paula - Matteo is an excellent professor!
Matteo is a great Professor. I have been taking lessons with him for the preparation of the GRE/GMAT. He is outstanding in teaching both theoretical concepts and practical mathematical applications. His teaching methodology is very effective for gaining a deep understanding of Mathematics in an intuitive way rather than a mechanical way. He thrives to find ways to teach you a “strategy” that works around your way of thinking rather than giving you “one way” interpretation. Matteo is also very friendly and intellectually curious I highly recommend him.
Jasmine - preparation of the GRE/GMAT
First of all Matteo is a teacher that really wants you to understand, and by this learn what you are doing. He is a very patient teacher and does not seem to mind stretching himself for you to achieve what you aim for - he is always up for sending some extra exercises or help if you have any problems.
Matteo helped me go from a person not having much understanding of maths to someone that could feel confident when studying a function that before would look uninterpratable. After his lessons I will not only be able to pass my exam, but I will be able to use what I have learned (and now understood) in the future for other subjects and/or programs.
Jørgensen - very patient teacher
Comment on

“Numbers and Functions”
Robert Burn

An excellent demonstration that even a subject such as Mathematical Analysis, traditionally considered by students to be tough, can be taught in a rigourous and yet comprehensible way. The reader is invited to solve a sequence of problems, that bring him to an autonomous construction of the main definitions and theorems.

“How Humans Learn to Think Mathematically”
David Tall

This book describes the development of mathematical thinking in kids and adults. It was illumating, when I first read it, and it still comforts and encourages me in my most difficult moments as a teacher, and as a student

Ideas and exercises

mathematical dialogues

16 November 2023
Not exceedingly complex
Putnam competition questions have often represented for me a very good motivation to train and further develop my knowledge in real analysis. In this post I want to show you another example of this k...
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5 January 2022
A bumpy ride
We take again inspiration from the Putnam competition, for an exercise on continuity and differentiability of real fuctions obtained by "stretching" a basic replica. Let us start from problem ...
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5 December 2021
Problem unraveling
Let us go back to Terence Tao's Solving Mathematical Problems, for another exercise. As done in a previous post, I would like to show an alternative solution to a problem the author proposes, th...
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2 December 2021
Extreme derivatives
Theorem. Let \(f\) be a real function, which is differentiable up to order \(n\) in  \(c \in \Bbb R\), for some positive integer \(n\). Suppose that \(f^{(n)}(c) \neq 0\), and that all preceedin...
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30 October 2021
Euclid strikes back
I found the following problem on Terenece Tao's "Solving Mathematical Problems". I propose, here, a synthetic approach based on simple Euclidean geometry concepts, instead of trigonometry, beacuse I ...
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