When Argentina's most famous singer dies in an accident during a concert, his unpopular wife, Nina Gluckstein, commits suicide. Yet, since public opinion of her was so low (and perhaps because she was Jewish), conspiracy theories abounded to explain her death without attributing to her the deep love or bravery implied by the official story.
As you can tell, none of that is mathematical. And yet, there is quite a bit of mathematics in this work of literature. It comes through the narrator, an 81 year old poet laureate (and former math professor) who tries to analyze Gluckstein's life so as to gain a better understanding of her own tragic love story as well as to develop a general theory of love. Apparently, it is because the book seems to say something about love in general that it has developed such a devoted following in much of the world (it was written in Spanish and extremely popular in Germany), but it is unfortunately difficult to obtain in the United States.
[Something about the way the book was written makes it seem like a combination of a memoir and a biography. The narrator seems to open up to you personally, and discusses Gluckstein as if you must have read about her in the papers. I wish to emphasize, however, that this is fiction. That the narrator and other characters seem so real is a testimony to the talents of their creator, Esther Vilar.]
Perhaps unsurprisingly, I was particularly interested in those sections of the book that play out a sort of competition between the fields of mathematics and literature. In some, mathematics seems to lose after the narrator becomes disillusioned:
(quoted from The Mathematics of Nina Gluckstein)
The real reason why I gave up my profession when I did  for four years I held a professorship of mathematics at the University in Buenos Aires  and began to write. That spring, while preparing a seminar on the calculus of probability, I discovered the work of Irish mathematician George Boole...He makes it clear that in the realm of logic, formalisms are possible similar to those of the world of number, that the laws governing human thought can be reduced to just as precise a sequential development as mathematical problems.
As happened to so many others, new worlds revealed themselves to me thanks to this book. ... I was firmly convinced that there is no phenomenon that cannot be reduced to formulas and that, once you had found out why individuals `act' in this or that manner in certain situations, all conflicts would be resolved for ever... Not for long. Because the more I looked for `human formulas' the more ambiguous everything I saw became. And so the mathematician changed almost imperceptibly into a poet...

Other remarks suggest a very high esteem for mathematics and are highly critical of writers:
(quoted from The Mathematics of Nina Gluckstein)
What force is contained in mathematical formulas....what sovereign brevity! For instance, how many pages would it take to translate Schrödinger's differential equation from quantum mechanics into ordinary language? And what marvellous universality this language possesses: whether it's Buenos Aires, Shanghai, Moscow  anyone who knows the symbols of mathematics can understand his counterpart! The precision with which even syllables are used: unequivocal, onetoone, ordered, partiallyordered, well ordered  an din each case a new dimension! ...
And isn't it us, the writers, who always make it seem despicable? No mathematician would dare boast about his bad style or his poor spelling. But the artist considers a bad grade in arithmetic a sure sign of intellectual superiority. He was chosen to be something better, hence his instinctive aversion to the world of numbers....
A person who can't think logically  and that's what mathematics is all about  looks for a loophole in uncertainty, vagueness, becomes an artist, or frequently also a writer or journalist...Logical thinkers are also capable of writing  what brilliantly formulated mathematical papers I read over the last few moths  but as a rule the don't because (a) they can do something else and (b) the sloppiness of this profession would drive them mad.

Of course, from my point of view, math and literature are not in competition but are two seemingly different disciplines with a great deal in common. Just as fiction sets up a scenario with the hopes of creating something beautiful which reveals hidden truths about the world, so do axiomatic systems and mathematical models!
Vilar seems to appreciate this similarity and builds upon it very well. Mathematical metaphors are utilized throughout the book and while I've seen attempts to address love mathematically in other works of fiction, I have never seen it done so successfully. Occasionally the mathematics itself is a bit off (the discussions of both Russell's paradox and the the fifth axiom of Euclidean geometry were garbled, at least in the English translation), but overall I felt that this was a very artistic and masterful combination of mathematics and literature.
