What is Neural-Symbolic Integration? by Gustav Šír
Symbolic artificial intelligence Wikipedia
Benefiting from the substantial increase in the parallel processing power of modern GPUs, and the ever-increasing amount of available data, deep learning has been steadily paving its way to completely dominate the (perceptual) ML. Lake and other colleagues had previously solved the problem using a purely symbolic approach, in which they collected a large set of questions from human players, then designed a grammar to represent these questions. “This grammar can generate all the questions people ask and also infinitely many other questions,” says Lake.
First of all, every deep neural net trained by supervised learning combines deep learning and symbolic manipulation, at least in a rudimentary sense. Because symbolic reasoning encodes knowledge in symbols and strings of characters. In supervised learning, those strings of characters are called labels, the categories by which we classify input data using a statistical model. The output of a classifier (let’s say we’re dealing with an image recognition algorithm that tells us whether we’re looking at a pedestrian, a stop sign, a traffic lane line or a moving semi-truck), can trigger business logic that reacts to each classification.
Neuro-symbolic AI aims to give machines true common sense
Again, the deep nets eventually learned to ask the right questions, which were both informative and creative. Better yet, the hybrid needed only about 10 percent of the training data required by solutions based purely on deep neural networks. When a deep net is being trained to solve a problem, it’s effectively searching through a vast space of potential solutions to find the correct one. Adding a symbolic component reduces the space of solutions to search, which speeds up learning. We introduce the Deep Symbolic Network (DSN) model, which aims at becoming the white-box version of Deep Neural Networks (DNN). The DSN model provides a simple, universal yet powerful structure, similar to DNN, to represent any knowledge of the world, which is transparent to humans.
1) Hinton, Yann LeCun and Andrew Ng have all suggested that work on unsupervised learning (learning from unlabeled data) will lead to our next breakthroughs. One of the biggest is to be able to automatically encode better rules for symbolic ai. “There have been many attempts to extend logic to deal with this which have not been successful,” Chatterjee said. Alternatively, in complex perception problems, the set of rules needed may be too large for the AI system to handle.
IBM, MIT and Harvard release “Common Sense AI” dataset at ICML 2021
In symbolic AI (upper left), humans must supply a “knowledge base” that the AI uses to answer questions. During training, they adjust the strength of the connections between layers of nodes. The hybrid uses deep nets, instead of humans, to generate only those portions of the knowledge base that it needs to answer a given question.
The General Problem Solver (GPS) cast planning as problem-solving used means-ends analysis to create plans. Graphplan takes a least-commitment approach to planning, rather than sequentially choosing actions from an initial state, working forwards, or a goal state if working backwards. Satplan is an approach to planning where a planning problem is reduced to a Boolean satisfiability problem.
Production rules connect symbols in a relationship similar to an If-Then statement. The expert system processes the rules to make deductions and to determine what additional information it needs, i.e. what questions to ask, using human-readable symbols. For example, OPS5, CLIPS and their successors Jess and Drools operate in this fashion. For the first method, called supervised learning, the team showed the deep nets numerous examples of board positions and the corresponding “good” questions (collected from human players). The deep nets eventually learned to ask good questions on their own, but were rarely creative. The researchers also used another form of training called reinforcement learning, in which the neural network is rewarded each time it asks a question that actually helps find the ships.
It does so by gradually learning to assign dissimilar, such as quasi-orthogonal, vectors to different image classes, mapping them far away from each other in the high-dimensional space. We’ve relied on the brain’s high-dimensional circuits and the unique mathematical properties of high-dimensional spaces. Specifically, we wanted to combine the learning representations that neural networks create with the compositionality of symbol-like entities, represented by high-dimensional and distributed vectors. The idea is to guide a neural network to represent unrelated objects with dissimilar high-dimensional vectors. In contrast to the US, in Europe the key AI programming language during that same period was Prolog.
The Frame Problem: knowledge representation challenges for first-order logic
All of this is encoded as a symbolic program in a programming language a computer can understand. A key factor in evolution of AI will be dependent on a common programming framework that allows simple integration of both deep learning and symbolic logic. The difficulties encountered by symbolic AI have, however, been deep, possibly unresolvable ones.
- Then, they tested it on the remaining part of the dataset, on images and questions it hadn’t seen before.
- From 2013 to 2022, AMD’s operating income increased from $89 million to $1.3 billion.
- The offspring, which they call neurosymbolic AI, are showing duckling-like abilities and then some.
- “In order to learn not to do bad stuff, it has to do the bad stuff, experience that the stuff was bad, and then figure out, 30 steps before it did the bad thing, how to prevent putting itself in that position,” says MIT-IBM Watson AI Lab team member Nathan Fulton.
We compare Schema Networks with Asynchronous Advantage Actor-Critic and Progressive Networks on a suite of Breakout variations, reporting results on training efficiency and zero-shot generalization, consistently demonstrating faster, more robust learning and better transfer. We argue that generalizing from limited data and learning causal relationships are essential abilities on the path toward generally intelligent systems. The power of neural networks is that they help automate the process of generating models of the world. This has led to several significant milestones in artificial intelligence, giving rise to deep learning models that, for example, could beat humans in progressively complex games, including Go and StarCraft.
Thus contrary to pre-existing cartesian philosophy he maintained that we are born without innate ideas and knowledge is instead determined only by experience derived by a sensed perception. Children can be symbol manipulation and do addition/subtraction, but they don’t really understand what they are doing. A certain set of structural rules are innate to humans, independent of sensory experience. With more linguistic stimuli received in the course of psychological development, children then adopt specific syntactic rules that conform to Universal grammar. Marvin Minsky first proposed frames as a way of interpreting common visual situations, such as an office, and Roger Schank extended this idea to scripts for common routines, such as dining out.
The automated theorem provers discussed below can prove theorems in first-order logic. Horn clause logic is more restricted than first-order logic and is used in logic programming languages such as Prolog. Extensions to first-order logic include temporal logic, to handle time; epistemic logic, to reason about agent knowledge; modal logic, to handle possibility and necessity; and probabilistic logics to handle logic and probability together. Semantic networks, conceptual graphs, frames, and logic are all approaches to modeling knowledge such as domain knowledge, problem-solving knowledge, and the semantic meaning of language.
System 1 vs. System 2 thinking
Fourth, the symbols and the links between them are transparent to us, and thus we will know what it has learned or not – which is the key for the security of an AI system. We present the details of the model, the algorithm powering its automatic learning ability, and describe its usefulness in different use cases. The purpose of this paper is to generate broad interest to develop it within an open source project centered on the Deep Symbolic Network (DSN) model towards the development of general AI. We believe that our results are the first step to direct learning representations in the neural networks towards symbol-like entities that can be manipulated by high-dimensional computing.
NSI has traditionally focused on emulating logic reasoning within neural networks, providing various perspectives into the correspondence between symbolic and sub-symbolic representations and computing. Historically, the community targeted mostly analysis of the correspondence and theoretical model expressiveness, rather than practical learning applications (which is probably why they have been marginalized by the mainstream research). Next, we’ve used LNNs to create a new system for knowledge-based question answering (KBQA), a task that requires reasoning to answer complex questions. Our system, called Neuro-Symbolic QA (NSQA),2 translates a given natural language question into a logical form and then uses our neuro-symbolic reasoner LNN to reason over a knowledge base to produce the answer.