“I am saddened to hear of Fahiem’s passing. He taught me AI when I was an undergraduate in Waterloo, and took me on as a research assistant. I spent a blissful summer learning Lisp, STRIPS, working late nights in the AI lab, and writing my first research paper with him on forward planning. I will never forget his intelligence, kindness, patience, and his warm smile. Rest in peace.”

– Yee Whye Teh
University of Oxford

“I am greatly saddened to hear this news. Fahiem was a good friend. And I’m not surprised the photograph of him accompanying this announcement had Fahiem with a big smile. He was always smiling and laughing. He lit up any room in which you found him. I had the pleasure to write half a dozen papers with Fahiem. Each was an enjoyable education. And he was a wonderful host for a number of month long visits I made to U of T when we wrote these papers. I shall miss him greatly. The computer science community has lost a very fine person.”

– Toby Walsh
University of New South Wales

“This message will resemble so many others. It was a privilege to experience Fahiem Bacchus as a teacher, and a unique joy to spend time with him outside the classroom. He was kind, fair, insightful, funny and had a rare calm presence. Fahiem was such a beautiful person. My deepest condolences to his loved ones and his community for this incredible loss.”

– Anastasia Bezerianos
Université Paris-Saclay

"A great loss for computer science. Condolences. A big hug to the family."

– Giovanni Acampora
University of Naples Federico II

“Fahiem was a Prince - always with a twinkle in his eye, he was as kind as he was brilliant. Fahiem, you will be missed!”

– Sara Franca
Queen’s University

“I was so deeply saddened to hear of Fahiem’s passing. He was a true gentleman, and a scholar. Fahiem had the most amazing and genuine smile that reflected his spirit of generosity and kindness. He had a strong dedication and commitment to the Department. I was fortunate and privileged to work with Fahiem when he was Acting Chair of the Department, working through lots of CS administrivia, and always that smile, every day!

I will miss him, his laughter and his amazing smile.”

– Sara Burns
Department of Computer Science

“Great professor, odd and unique sense of humour. My experience with him in CSC384 was fantastic. Always smiled and said hello when I walked by him (daily) in the corridor between Sandford and Pratt.”

– Kashav Madan
University of Toronto alumnus

“Prof. Bacchus's Intro to AI class was the first course I had taken at U of T; even more than the excellent course content, it was Prof. Bacchus's enthusiasm towards his subject and warmth towards his students that got me interested in the field...his incredible patience, kindness, and intelligence will be missed at U of T and around the world.”

– Andrew Gritsevskiy
University of Toronto

‪”I’m so very sorry to hear this. I worked with Fahiem on IJCAI - he was a gentle and good natured soul, and I liked him very much. All my love to his family & friends.‬”

– Michael Wooldridge
University of Oxford

"I am truly sad to be writing this message. I am a family but also a dear friend. I am honoured and privileged to enjoy the company of this kind, brilliant individual. I will continue to pray that Fahiem finds eternal peace. RIP dear Fahiem❤️❤️"

– Nimoon Doobay

“I am so sorry to hear the news of Fahiem Bacchus passing. He was a brilliant researcher, a caring teacher and mentor, a dedicated member of the community, and a good friend to everyone who knew him. He was a lovely person with a kind heart and I will miss him.”

– Marie desJardins
Simmons College

“I am deeply saddened by the news of Fahiem’s passing.

Professor Fahiem thought me my first ever AI course at University of Toronto and I had the privilege of having him in my PhD. committee. It is fair to say that I wouldn’t be who I am today if it was not for him.

I will always remember Fahiem’s kindness, big smile, and intelligence.

My deepest condolences.”

– Shirin Sohrabi
Department of Computer Science alumna

"I am deeply saddened by the news of Faheim's passing. I am a junior member in the faculty and interacted with him on multiple occasions, particularly as we discussed the future course of the department. Faheim, besides being a scholar, was a remarkable mentor, and I am glad to have received his advice over the last two years.

His presence in the group lifted our spirits even in times on academic disagreements. He was a true leader and visionary. The community and his colleagues will dearly miss him."

– Animesh Garg
Department of Computer Science

“Fahiem introduced me to AI when I was an undergrad at Waterloo in the mid 90s, and also acted as an excellent supervisor and mentor to many students at Waterloo and Toronto over the years.”

– Mary Ellen Foster
University of Glasgow

"I had the privilege and honour of having Fahiem on my PhD committee. And while I never did take a course from him, it was his teaching that I remember best. Having missed my chance to sit in on his graduate class (timing was off and he wasn't teaching it when I needed a credit, if I recall), Fahiem graciously worked with me to provide all the lecture content and Q&A needed to bootstrap my academic career. I have a vivid memory of pouring over printouts of Fahiem's slides, and then coming to him later for advice on just how SAT solvers work. Upon seeing my interest, he also promptly invited me to join his lab reading group to learn more (and made sure there was enough sweets ordered to include me as well!). He was exceptionally gracious with his time, and I wasn't even a(n official) student of his at the time. I suspect many fall under the same category -- learning a tremendous amount from Fahiem, regardless of if you were formally meant to be.

He was a treasure to so many, and will be sorely missed. RIP, Fahiem."

– Christian Muise
Department of Computer Science alumnus

“Fahiem and I overlapped for a couple of weeks at Waterloo when I was finishing up my master's degree. Then we met again and got to know each other at CP conferences.

Fahiem was an excellent researcher, a great speaker, and a super nice person. RIP, my friend.”

– Jimmy Lee
University of Waterloo alumnus

“Like most of you have probably written, Fahiem was always smiling, always looked happy. It's his smile that I think most people will remember and always picture him.”

– Jankie Ramsook
Department of Computer Science

“I remember Fahiem from his computer science lectures at the university. He was an outstanding, intelligent and thoughtful professor, and this is a huge loss to us all.”

– Nataliya P

"Sometimes the best, the brightest and the kindest leave us far too early. Fahiem was one of them. He will be missed by many of us in the AI Community, to which he contributed so much!"

– Holger Hoos
RWTH Aachen University

“RIP Professor Fahiem Bacchus. He was my professor in the Department of Computer Science at the U of T. He taught me AI. I remember him as always friendly and helpful. He positively influenced my career as a researcher and educator probably more than he ever realized.”

– Richard Zhao
Department of Computer Science alumnus

“I was shocked and greatly saddened to hear of Fahiem's so untimely death. I extend my deepest sympathy and condolences to his family members.

Fahiem was my doctoral advisee at the University of Alberta, and it is distressing for an advisor to lose an academic "child", especially one so amicable, brilliant, and dedicated. Fahiem was an ideal doctoral student, transforming vaguely formulated research ideas we had discussed into theoretically deep and consequential projects. His pioneering work on representing and reasoning with probabilistic knowledge, within the framework of first-order logic, was profoundly influential, leading to his interactions and collaborations with other eminences in this field, such as Henry Kyburg, Joe Halpern, Adam Grove, Daphne Koller, and Craig Boutilier. I was very impressed by his branching out in his subsequent career at Waterloo and the University of Toronto into areas such as Bayesian networks, planning, constraint networks, and satisfiability; all of his work was brilliant, original, and highly impactful. I was looking forward to seeing a continuing stream of exciting work from him and his students; and most of all, I was looking forward to continuing occasional encounters with him. It had always been a joy to reconnect with him, to hear his talks, and get his insights via email. I will truly miss him.”

– Lenhart Schubert
Former PhD advisor at University of Alberta

“I am heartbroken and devastated.

Fahiem was a big part of my professional life even before I knew him personally: his paper on counting kick-started the development of practical counters, and I have spent the past decade building counters.

I had asked Fahiem to be a mentor when I started my faculty career at NUS in 2018, and he readily and kindly agreed. Since then, he has been the best mentor one could have asked for: he was always generous, kind, and optimistic in every meeting and every email (including the ones from the last month).

He achieved many simple yet technically deep results, and he nudged the rest of us, through questions after talks and discussions over coffee/meals, to settle for nothing less.

Over the past few years, I would excitedly inform him of new results and receive his authentic comments; Fahiem was always authentic: there was never any pretense.

I will miss Fahiem very much.”

– Kuldeep S. Meel
National University of Singapore

“Fahiem was my PhD advisor, my mentor, and a person I admire greatly. He was humble, generous, and a quiet genius.

Apart from being brilliant with high-level ideas, Fahiem was an exceptional writer. When writing, he emphasized clarity and ‘getting the story right.’ He was also an exceptional programmer. He would implement many of his ideas himself, and taught me so much all the way down to low-level details.

Fahiem believed strongly in doing good science. Something I was always amazed at was his special ability to lean back and visualize difficult concepts. He had tremendous intuition in knowing which ideas were worth exploring and which were not.

Lastly, Fahiem was very kind and fun to be around. When things got difficult, he knew how to lighten the situation with a joke or a big smile. I am extremely grateful to him and I will miss him dearly.”

– Randy Hickey
Department of Computer Science

“Fahiem was a wonderful person and a great researcher. I really enjoyed discussing research with him over the years and working with him on organizing the IJCAI conferences. I think we will all miss him very much!”

– Craig Knoblock
University of Southern California

“Fahiem, you have been an inspiration for so many of us, myself included, as a colleague, as a leader, as a researcher, as an educator. You will always be in our hearts.”

– Marsha Chechik
Past Chair, Department of Computer Science

“I am deeply saddened to hear of Fahiem’s passing. I had the good fortune of having Fahiem as my PhD advisor. The AI community has lost a passionate, brilliant researcher, and U of T has lost one of its leaders.

I will never forget his review of the first draft of the first paper we co-authored. He returned the draft with every inch of the paper covered in red ink! But as he handed it to me, he flashed his warm, broad smile, and reassured me that it was a good paper. It was this moment that I think best encapsulates Fahiem for me. Brilliant, insightful, joyful, gracious and a wonderful kind heart. He has touched so many during his time with us, and will be sorely missed.”

– Matthew Kitching
Department of Computer Science alumnus

“Fahiem was both an outstanding technical researcher and a wonderful colleague. I have many fond memories from the sabbatical time that he spent in our lab at SRI. He will certainly be missed in the research community.”

– Karen Myers
SRI International

“Fahiem came to the University of Rochester to work as postdoc with my thesis advisor, Henry Kyburg, as I was finishing my PhD. Fahiem's work really pleased Kyburg and the AI community. I cannot ever forget how he sat in a chair and smiled, even during a debate over ideas and approach. It's good to see his career led to the top, at Toronto, with an impressive citation record. I look forward to sitting down and reading his works so that I can remember the man behind them.”

– Ronald Loui
Case Western Reserve University

“So sad to hear this news. I can still remember the seminar that he gave when he visited us in Hong Kong a few years ago, on solving stable matching problems using SAT solvers. As always, he made hard problems sound easy. I’ll miss him, as a colleague, a friend, and a wonderful human being.”

– Fangzhen Lin
The Hong Kong University of Science and Technology

“I feel extreme sadness by the passing of Fahiem. I was lucky to have known him for close to 20 years since I joined the Department in 2002. Fahiem is someone you could always count on to be the voice for reason and integrity. His calm demeanour and thoughtful approach are a source of inspiration for me. I will miss him.”

– Eyal de Lara
Chair, Department of Computer Science

“I am shocked and saddened like I’m sure everyone who knew Fahiem is. A great researcher, and a truly lovely person. My deep condolences.”

– Yoav Shoham
Stanford University

“I am deeply saddened to learn of Fahiem's passing away. He was an influential mentor and a great friend to me. I first got in touch with Fahiem in 1990 while discussing a paper I had co-published at AAAI Conference. Two years later, he was on my PhD thesis jury and offered me a postdoc at the University of Waterloo. He welcomed me in Waterloo almost as a family member and introduced me to his family and colleagues, sharing good meals and wine on many occasions. I spent nine months working with him on new approaches to planning with search-control knowledge. I have always known Fahiem as a brilliant mind, with great kindness, sensible to the suffering of people worldwide. My suspension of academic research to work in the industry meant we did not get in touch for the last few years, but I always had him and his family in my thoughts. He left too soon, and I will miss him very much.”

– Froduald Kabanza
Former postdoctoral fellow, University of Waterloo

“Fahiem was an outstanding teacher and collaborator for a young PhD student. He asked piercing questions and worked directly on the most important problems. It was a pleasure to have him on my committee and he will be missed.”

– Andrew Perrault
The Ohio State University

“I am very sad to hear of Fahiem’s passing. I had the pleasure of interacting with him through IJCAI and when he visited SRI. He was an outstanding researcher with a warm personality. He will be missed.”

– Ray Perrault
SRI International

“I am very saddened to hear the news of Fahiem’s passing. Fahiem is one of the kindest and most approachable faculty members in the department. I remember his genuine, warm smile at times when we walked and chatted on the corridor in Pratt. I also remember his unique senses of humour and wisdom over the dinner table, and his thoughtful remarks on the status and the future of the department and the field of CS. Fahiem’s passing is both a shock and a great loss to our department, and I send my deep condolences to his family.”

– Yang Xu
Department of Computer Science

“I am saddened to hear the news. It is disheartening to pass by Fahiem's office at Pratt and not see him there anymore. An incredible loss for the computer science community! Fahiem's significant contributions to science and his memory will stay with us forever.”

– Kazem Cheshmi
Department of Computer Science alumnus

“When I entered the SAT field more than two decades ago Fahiem was an established senior researcher I really looked up to and I still feel honored, as we were getting older, he became a close colleague too. Beside contributing intriguing SAT papers written in an exceptionally crisp and clear style he also strongly supported the community particularly in participating in the organization of the conference throughout all these years, first informally and later also as member of the board of the SAT association. We owe him great respect for also serving as chair of the association more recently. I really was hoping to continue to be able to engage with him in these organizational matters, but also exchange more students and of course having those intense fruitful technical discussions I vividly remember at the conference all over the planet for twenty years. It is a great loss to us all.”

– Armin Biere
Albert-Ludwigs-University Freiburg

“I first met Fahiem as a grad student at Waterloo. He was very approachable and had a calm manner of teaching. But what I remember very fondly is his giggle. We often chatted here at U of T when he was warming up his home brought lunch, and were laughing together about something or other. He was a warm and kind man. Fahiem, we will miss you both as a scholar and a friend.”

– Relu Patrascu
University of Toronto

“Fahiem and I first met when I was a graduate student and he was a new Assistant Professor at the University of Waterloo. Over the next thirty years or so, our friendship and research collaborations grew. One particularly fond memory I have is co-organizing CP 2004 in Toronto with Fahiem. Fahiem insisted that the conference dinner be at the top of the CN tower. The food and wine were good, but the highlight was seeing many of the serious researchers attending the conference jumping up and down on the glass floor 500m above the ground at the end of the night. I will hold onto these and many other memories. I will miss you, Fahiem. Rest in peace.”

– Peter van Beek
University of Waterloo

“Fahiem was an exceptionally talented, kind and approachable professor — a constant inspiration to all the members of our lab. I remember the eagerness most of us had to take his graduate class on SAT and how we looked forward to discussing our ideas with him in hope of getting a spark ..if not just for his happy, calming effect. No matter his constraints, he would almost always make time to help.

He will be missed by all of us — the loss will be truly felt across the U of T + SAT solver research community.”

– Vincent H
University of Toronto

“I am Fahiem's sister and I wish to thank you all for your reflections and your condolences to our family. Your thoughts and your pain at his passing is heartfelt and sincere. We appreciate reading them all, it gave us joy to know how much he added to your lives as well, and to know how much he was loved, thank you all so much.

My brother was gentle and so kind, sensitive, very generous and actually was quite shy when he was young. He accepted everyone, he didn’t like conflict and was never judgemental. He also had an excellent and quite unique sense of humor. I have many warm and very happy memories of our childhood years. I remember he would love to say things to people that would ‘drive them crazy’ — but not necessarily because he actually believed what he was saying — but simply cos it 'drove them crazy!’ It was totally hilarious — to me, anyway — but I also have the same sense of humor.

As we entered adulthood in the mid 70’s Fahiem was at university and I was married and started having children. He enjoyed his nieces and nephews tremendously, and visited us often. In fact many of the pictures I have of my kids at that time were taken by him, he also liked photography. I remember when Fahiem would have the big boxes of computer code cards, and he’d laughingly tell me stories of poor souls who would drop their boxes and the cards would scatter — to Fahiem it was the definition of ‘a disaster’ and ‘if I don’t laugh I’d cry for them’ at the same time. When he got into the field of Artificial Intelligence I would tease him and say: “I always knew you were 'artificially’ intelligent.”

Once he got married and moved out of Alberta, I unfortunately didn’t get to see him nearly as often. He was far more busy and focused on his work and his life. He did come to visit but it wasn’t often, nor was it the same. As the saying goes: ‘Life got in the way.’

Thankfully, over the last 10 years, Fahiem and I became very close again. We had to collaborate due to our mother’s dementia. With our mom being in Edmonton we took on the joint responsibility of her care. And during the last 8+ years we did regain the warmth of our youth, and the laughter from our particular style of humor. Fahiem was incredibly intelligent — so he was very witty, quick and even kind of humorously sarcastic — which is also totally my style! Many people are unaware that “Fahiem” (spelt Faheem) actually means ‘intelligence’... he certainly lived up to his name.

When Fahiem was diagnosed last May I never, in a million years, imagined this outcome. As I headed to Toronto 2 weeks ago I never thought it would be so quick.

I am so incredibly grateful my daughter and I were able to actually visit with him shortly before his passing. We reminisced about moments in our childhood, we laughed, he talked about our mother’s amazing cooking, and more... it was priceless.

There are no words to describe my feelings, no words for this profound and tragic loss to our family. Yet I am so grateful to have been a huge part of his life... he was the best brother... uncle and son as well. I’m certain he was also the BEST husband and father.

For all his amazing accomplishments Fahiem, to me, was my little brother, and a man of great character. My entire family had absolutely NO idea of his status within his field. We had no concept of his accomplishments and contributions to AI. Until now... Fahiem was so humble, he never told us. He never bragged, he was never one to show off or make one feel ‘less’, which speaks volumes as to his character...

My heart is heavy for those he leaves behind. He doesn’t get the retirement he so looked forward to enjoying. Nor does he get the years ahead to see Luke graduate, or to marry, or to have children... nor does my brother get to enjoy all the future plans made with his much loved wife Jessica... and it can seem life is so unfair.

But Fahiem didn’t complain, he was neither angry nor resentful about all he would miss... that wasn’t his character. Instead he was grateful for all he DID get to do in his life. Grateful for his friends, colleagues and students. Grateful for the family he loved: his sisters, his brother, his nieces and nephews, his great nieces and nephews... and most especially he was incredibly grateful for his wife Jessica and his son Luke — they were his life.

So I do not say goodbye my dear brother, I only say ‘farewell for now, until we meet again.’

As is written on our parents headstones: ‘Where there is Love there is no parting...’”

– Zeeda Bacchus