Can love be reduced to a simple, mathematical equation? Is love a quantifiable emotion? Or, does love defy all definitions placed in neat little boxes expressed in varied ways such as "romance", "desire", "passion" so far it is connected, mainly, between a man and a woman?

According to Srijit Mukherjee's intriguing film with its puzzling title X=Prem, love (between a heterogenous couple) is the most intriguing of relationships in the world. You never know when a tragic accident might keep you alive, but snatch away ten years of memory from you. Life, after all, is more intriguing than love.

This is what happens in Srijit Mukherjee's twisted but deeply emotionally moving film on love, lost and found. One fine morning, lying in a hospital bed bandaged with tubes running out of/into his body, Khilat, a 28-year-old software engineer, caught in a terrible accident, cannot recognize his fiancée Joyee. He has lost 10 years of memory and can recall only till he was 18 years old.

The couple approach Dr. Kauffman who is experimenting with neurological implants and transplants, scientifically not proven and therefore, considered illegal. The couple, Joyee, madly in love with Khilat who fails to recognize her, decides to go ahead with the experiment.

Khilat gets his intellectual memory back, but not his emotional memory. He still has no clue about who Joyee is, what happened to them before the accident, where they met and fell in love. He does not remember the accident either. How a second neurological intervention that places a strange demand of the couple to get back his emotional memory makes the rest of the film.

Now, Joyee is Khilat's 'ex' but Khilat is neither her ex nor her present. This gives the director the opportunity to move back and forth into the lovers' past, back to their present dilemma as Joyee stubbornly sticks beside him.

Mukherjee pays his own tribute to Michel Gondry's Eternal Sunshine Of The Spotless Mind (2004). This film goes one better though those who have neither read or read about the book The Vow (2012) or watched the film, it may mean nothing.

The Vow was directed by Michael Sucsy, inspired by the true story of Kim and Krickitt Carpenter. Ten weeks after their wedding on September 18, 1993, the couple was involved in a car accident. Krickitt suffered a brain trauma, which erased all memories of her romance with Kim as well as of their marriage. Kim was deeply in love with his wife, although she viewed him as a stranger after the accident.

Mukherjee simply changes the genders of the couple in which the wife loses her memory, not the husband. The wife comes out of her coma and finally recognises her husband and this strange coincidence is credited to their deep devotion to Christian faith and Christ.

However, Mukherjeedoes not bring in the divinity factor at all. He has turned the amnesia to a more scientific explanation in X=Prem, seen from his reference to Eternal Sunshine Of The Spotless Mind, where Dr. Kauffman says it would have made his explanation easier to follow if Khilat and Joyee had watched this film.

This critic loved the film despite its "inspiration" because not only does it convincingly present a unique perspective on love, memory lost and remembered, but has shaped it to be a performance-based film. It has beautiful songs, a lot of poetry on the sound-track through voice-overs, and even a beautiful tango number that introduces the senior student Joyee to the new entrant and younger Khilat.

his is one of the best orchestrated scenes in the film. As Khilat 'teaches' her to do a tango, he says that they will create their own music and nonchalantly, dressed in the Bengali dhuti and punjabi, performs a beautiful duet with Joyee whose expression changes from slight to amusement to surprise to fascination. And love is born. Srijit has given the film a truly Bengali cultural and social identity though the major characters speak often in English.

The brightest side of the blooming romance between Khilat and Joyee is that Joyee is the more aggressive partner between the two. She engineers every 'bold' move from smoking pot, drinking alcohol, having sex, to skinny dipping – marking a first in contemporary Bengali cinema.

All this is done with feeling and aesthetics that never seem vulgar and throw all gender questions straight out of the window. Locations that the lovers visit include a Hindi-cinema-type of wedding at a forgotten temple inside a cave headed by a priest who reads out the vows, all in fun.

The film shows an image of a bunch of Bengali, upper-middle-class, English educated youngsters who truly enjoy their college life as one large circle of fun, drinks, dances, rebellious movements, and do not go by the moralistic codes of a middle-class society.

Mukherjee's decision to play with music makes it one of the most important pillars of the narrative that enriches the film. The six tracks composed by debutant music composer Sanai and sung by Shreya Ghoshal, Arijit Singh, Samantak Sinha and Sahana Bajpaie add to the film's texture, as do the romantic lyrics by Dhrubajyoti Chakraborty.

Subhankar Bhar has given a special texture with his B&W cinematography, which is another plus point. Anindit Roy's sound gives the film an edge. This also helps the time zone leaps which form the structure of the film, and the editors need to be complimented as well.

The best part is Srijit's intelligent decision of introducing three new faces with Anindya Sengupta as Khilaat, Shruti Das as Joyee and Madhurima Basak as the confident wife of the third angle of this triangle, Arnab (Arjun Chakraborty).

They have performed brilliantly and fit into their roles like a glove. Anindya's blank and confused reaction when Joyee narrates their past adventures as he just cannot relate to them is telling. Arjun, though he has less footage than the two major characters, and minimum dialogue, does extremely well. Arnab and his wife Aditi present a completely different picture of love within marriage and this too, adds to the film.

Srijit's "inspiration" from two international films does not quite take away his unique ideation of his film, the music he has decided on and the complete "Bengalisation" except too much English in the dialogue and too many intellectual references through poetry. The small reference of Joyee's being a victim of sexual abuse is like a sharp-edged knife that cuts into the beautiful lyricism of the film.

Yet, all said and done, the mathematical equation evolved in X=Prem stands testimony to the wonderful quality of the film.