#3726 Applying AI to Discover and Improve Algorithms; ++Improving QC Algorithms
#3726 Applying AI to Discover and Improve Algorithms; ++Improving QC Algorithms
#3726 Stephen Wolfram wrote a book about Combinators. As an AI developer and applier, why should I care?
You should care because combinators, especially through Stephen Wolfram's lens, offer a fundamentally different and more basic perspective on computation itself. They challenge the way you might think about code, intelligence, and the search for new algorithms.
For an AI developer, this isn't just an academic exercise. It has implications for how we understand and build intelligent systems.
A Deeper Model of Computation
At its core, AI is applied computation. You're likely familiar with Turing machines as the theoretical bedrock of what computers can do. Combinators are an alternative, and in some ways simpler, model of Turing-complete computation.
Instead of a machine with tape and a head, you have a system based on rewriting expressions using a few primitive functions (like S and K). Everything, including numbers, logic, and data structures, emerges from applying these simple rewrite rules over and over.
Why it matters: Understanding this provides a more profound grasp of computation's essence. It's like an AI engineer understanding how a transistor works instead of just knowing how to use a high-level programming language. It reveals that the complex software you build is just one possible structure built upon a much simpler, more fundamental layer of logic.
The Power of Simplicity and Emergent Complexity
Wolfram's work consistently champions the idea that complex behavior can arise from very simple rules.
This directly parallels a central theme in modern AI, especially in neural networks. The intricate, intelligent-seeming behavior of a large language model emerges from the repeated application of a very simple operation: a weighted sum followed by a non-linear activation function, scaled across billions of "neurons."
Why it matters: Studying combinators provides a clean, theoretical sandbox for exploring the principle of emergent complexity. It encourages a way of thinking where you don't just engineer a complex solution top-down, but you search for the simple underlying rules that will generate the solution you need.
A New Frontier for Program Synthesis
A holy grail of AI is program synthesis—having an AI write useful code on its own. The search space of all possible programs in a language like Python is unimaginably vast and complex.
Combinators offer a more fundamental search space. Instead of searching through lines of code, you can search through the space of possible combinations of primitive functions. Wolfram's project is, in essence, a massive search through this "computational universe" to find interesting and useful programs.
Why it matters: This reframes program generation. It becomes less about syntax and structure and more about exploring a mathematical space. AI techniques like reinforcement learning and evolutionary algorithms are perfectly suited for these kinds of search problems.
You could potentially use AI to discover novel algorithms by exploring the "ruliad" (Wolfram's term for the entangled space of all possible computations).
Rethinking Symbolic AI
While deep learning dominates AI, symbolic AI—which deals with logic and explicit rules—is still crucial for reasoning, verification, and interpretability. Combinatory logic is a powerful symbolic system. It's all about the manipulation and transformation of expressions.
Why it matters: As we try to build more robust and trustworthy AI, combining neural and symbolic methods is a major area of research. A deep understanding of a fundamental symbolic system like combinators provides a powerful tool for thinking about how an AI might reason, prove things, or manipulate abstract concepts in a verifiable way. 🧑💻
For anyone looking to explore combinatory logic, Mathematica is arguably one of the most powerful computational environments available. Here’s a breakdown of its capabilities:
1. Core Combinator Representation
The Wolfram Language has built-in symbols for the most common combinators, treating them as fundamental objects.
CombinatorS
,CombinatorK
,CombinatorI
: These are the foundational S, K, and I combinators.CombinatorB
,CombinatorC
,CombinatorW
,CombinatorY
: Support extends to other important combinators used in logic and for creating fixed points (recursion).
Expressions are created using the standard nested function application syntax that is idiomatic in the Wolfram Language. For example, the expression S(K(S))K
would be written as:
CombinatorS[CombinatorK[CombinatorS]][CombinatorK]
This direct representation is crucial because it allows you to construct and manipulate combinator expressions as symbolic data.
2. Symbolic Evaluation and Transformation
The power of the Wolfram Language's symbolic nature is fully leveraged for combinators. You can define the reduction rules and use functions like ReplaceRepeated
(short form //.
) to evaluate a combinator expression.
Example: Proving I can be derived from S and K
The expression S K K
is equivalent to the identity combinator I
. We can demonstrate this by applying the reduction rules for S
and K
:
(* Define the reduction rules for S and K *)
rules = {
CombinatorS[x_][y_][z_] -> x[z][y[z]],
CombinatorK[x_][y_] -> x
};
(* Define an expression for S K K applied to a variable 'a' *)
expr = CombinatorS[CombinatorK][CombinatorK][a];
(* Repeatedly apply the rules until the expression no longer changes *)
expr //. rules
This computation will yield a
, demonstrating that CombinatorS[CombinatorK][CombinatorK]
behaves identically to CombinatorI
.
3. Advanced Analysis and Visualization
Beyond basic evaluation, Mathematica offers sophisticated tools, many available through the Wolfram Function Repository, that are specifically designed for studying the behavior of these simple systems.
FindEquationalProof
andFindCombinatorProof
: These functions are automated theorem provers for combinatory logic.You can provide an identity (e.g., B x y z == x(y z)
), and the system will attempt to derive it from the fundamental axioms of S and K, returning aProofObject
if successful.CombinatorExpressionGraph
: This function visualizes a combinator expression as a tree, which is invaluable for understanding its structure.CombinatorEvolutionGraph
: This powerful visualization tool shows the step-by-step evaluation of a combinator expression.It can generate a graph where each node is a state of the expression and the edges represent reduction steps. This allows you to explore the "multiway" evolution of the system, a key concept in Wolfram's physics project.
4. Philosophical Integration
As Stephen Wolfram's writings suggest, the principles of combinators are part of the Wolfram Language's deep ancestry.
Everything in the language is a symbolic expression of the form head[arg1, arg2, ...]
. This structure is directly analogous to the application of functions in combinatory logic. This philosophical alignment makes working with combinators feel remarkably natural and seamless within the Mathematica environment.
In summary, Mathematica doesn't just "support" combinators with a few add-on functions. It provides a comprehensive ecosystem for defining, evaluating, proving theorems about, and visualizing them, reflecting their status as a fundamental concept in Stephen Wolfram's view of computation.
How could genetic programming be used with combinators to "discover" and develop new and improve algorithms?
Excellent question. Genetic programming can be combined with combinators to create a powerful, albeit computationally intensive, system for automatically discovering and improving algorithms. The core idea is to use the principles of biological evolution to explore the vast mathematical space of programs that can be built from these fundamental "atoms of computation."
Here’s how that process would work:
The Core Concept: Combinators as Computational DNA 🧬
Think of the basic combinators, S and K, as the adenine (A) and guanine (G) of a computational DNA. By arranging them in different sequences and structures (expressions), you can create a "genome" that encodes a specific algorithm.
Genetic programming (GP) is an AI technique that mimics evolution. It doesn't evolve data to fit a model; it evolves the models (or programs) themselves. By using combinator expressions as the "genetic material," GP can search for novel algorithms without human preconceptions about what a program should look like.
The Evolutionary Process: A Step-by-Step Guide
The process follows the classic genetic programming loop, but it's specifically adapted to manipulate combinator expressions.
1. Representation (The "Chromosome")
Each individual "creature" in the population is a program represented as a tree structure of combinator expressions. For example, the algorithm S(K)(S)
would be a tree with S
at the root and two children, K
and S
. The inputs to the algorithm (e.g., numbers from a list to be sorted) are treated as "terminals" or leaves of the tree.
2. Initialization (The "Primordial Soup")
The process begins by creating an initial population of hundreds or thousands of randomly generated combinator expression trees. Most of these initial "algorithms" will be completely useless, producing chaotic or trivial results.
3. Fitness Evaluation (Survival of the Fittest)
This is the most critical and domain-specific step. You must define a fitness function that scores how well each program solves a specific problem.
Example Problem: Sort a list of numbers.
Fitness Test:
Run each combinator program with the unsorted list as input.
Compare the program's output to the correctly sorted list.
The "fitness score" could be the number of elements in the correct position. A perfectly sorted list yields the highest possible score.
Programs that produce gibberish or fail to terminate within a time limit receive a score of zero.
4. Selection (Choosing Who Gets to Breed)
Based on their fitness scores, the best-performing programs are selected to "reproduce." Programs with higher scores have a higher probability of being chosen, mimicking the principle of natural selection.
5. Reproduction (Creating the Next Generation)
New programs are created using two primary genetic operators:
Crossover (Sexual Reproduction): Two high-scoring "parent" programs are chosen. A random subtree (a sub-expression) is selected from each parent and they are swapped. This combines the "genetic material" of two successful programs in the hope of creating an even better "offspring."
Mutation (Random Variation): A single parent program is chosen. A small, random change is introduced into its tree. This could be swapping one combinator for another (e.g., changing an
S
to aK
) or replacing an entire subtree with a new random one. Mutation adds new genetic diversity to the population, preventing it from getting stuck in a local optimum.
6. Repetition
The cycle of evaluation, selection, and reproduction is repeated for many generations. Over time, the average fitness of the population tends to increase, as the evolutionary pressure pushes the system toward programs that are better and better at solving the target problem. The final result is the highest-scoring program found during the entire run.
Why This Is a Powerful Idea
Truly Unconstrained Search: Because combinators are so fundamental, this method isn't biased by human-designed programming languages or conventional algorithm design patterns. It can discover completely alien, yet highly efficient, ways of performing computations.
Minimalism and Emergence: It demonstrates how complex, purposeful algorithms can emerge from a system with just two simple rewrite rules and the process of evolution.
Automated Discovery: It holds the potential to automate the discovery of new algorithms for niche problems in fields like optimization, cryptography, or signal processing, where novel approaches are highly valuable.
Challenges
Computational Expense: Evaluating thousands of programs over thousands of generations is incredibly resource-intensive.
Bloat: GP is notorious for producing "bloat"—programs that grow enormously large and inefficient without a corresponding increase in fitness.
Intelligibility: The discovered algorithm will likely be a massive, inscrutable nest of S's and K's. While it might work perfectly, understanding how it works is a significant challenge.
Describe the types of algorithms (e.g. sorting, matrix manipulation, etc.) where this could be usefully applied
This evolutionary approach is best suited for problems where the desired algorithm can be expressed as a pure function (inputs map to outputs without side effects), a clear, fast fitness function can be defined, and where novelty or non-obviousness in a solution is valuable. It's less suited for algorithms requiring complex state management or human readability.
Here are the specific types of algorithms where this could be usefully applied.
Optimization and Heuristics 🗺️
This is a prime application area. Many complex optimization problems (like the Traveling Salesperson Problem or circuit layout) are too hard to solve perfectly. Instead, we rely on heuristics—clever "rules of thumb" that build good, but not necessarily perfect, solutions quickly.
How it works: GP could evolve a heuristic function. For the Traveling Salesperson Problem, the combinator program wouldn't be a full sorting algorithm, but a function that, given a partial tour and a set of remaining cities, decides which city to visit next.
Why it's a good fit: The fitness function is straightforward (e.g., the total length of the tour produced by the heuristic). We don't need to understand why the resulting rule works, only that it produces short tours efficiently. This is a search for a novel, effective strategy.
Cryptography and Hashing
The goal of cryptography is to create transformations that are easy to compute in one direction but incredibly difficult to reverse. This often involves creating functions that behave in complex, pseudo-random, and non-linear ways.
How it works: GP can be used to evolve new hash functions or substitution-permutation networks (core components of block ciphers). The fitness function would involve a battery of statistical tests to check for desirable properties like the avalanche effect (a small change in input creates a massive change in output) and resistance to standard cryptanalysis attacks.
Why it's a good fit: The "black box" and unintelligible nature of the evolved combinator expression is a feature, not a bug. We want functions that are obscure and don't reveal any simple mathematical structure that could be exploited. This is a perfect area for discovering "alien" math that is useful precisely because it's so non-obvious.
Signal/Image Processing and Compression 📸
Many tasks in this domain involve applying a filter or transformation function to data. This could be for sharpening an image, removing noise from an audio signal, or finding a compact data representation for compression.
How it works: GP can evolve a filter function that takes a pixel and its neighbors as input and produces a new output pixel. The fitness function would measure the difference between the filtered image and a "perfect" target image (e.g., removing noise from a corrupted image to match the original).
Why it's a good fit: Filters are self-contained, pure functions. There is immense potential for discovering novel, non-linear filters tailored to specific types of noise or for creating unique artistic effects. Similarly, for compression, GP could discover a weird but effective transformation that makes data more compressible by a standard algorithm like Huffman coding.
Specialized Mathematical Functions
This method can be used as a tool for automated scientific discovery to find functions with specific mathematical properties or to create highly optimized approximations.
How it works: You could use GP to find a function that fits a set of data points with minimal error or to discover a fast approximation for a complex function (like a trigonometric or logarithmic function) that is highly accurate over a specific input range. The discovery of novel matrix multiplication algorithms like Strassen's method is a classic example of a non-intuitive solution that this approach could theoretically find.
Why it's a good fit: This is a pure search through the space of possible computations. For highly specific or constrained domains, an evolved, custom function could outperform general-purpose human-designed algorithms.
Provide the symbolic representation of matrix multiplication
If two matrices, A of size and B of size , are multiplied, the resulting matrix C will be of size .
The symbolic representation for any element Cij (in the i-th row and j-th column) of the resulting matrix C is:
Breakdown of the Formula 🧮
Cij: The element in the i-th row and j-th column of the final matrix C.
Aik: The element in the i-th row and k-th column of the first matrix A.
Bkj: The element in the k-th row and j-th column of the second matrix B.
∑k=1n: This is the summation symbol. It means you sum the products of AikBkj for all values of k from 1 to n. The value n is the number of columns in matrix A and the number of rows in matrix B.
In simple terms, to find the value at a specific position in the resulting matrix, you take the dot product of the corresponding row from the first matrix and the corresponding column from the second matrix.
Example
Let's multiply two matrices, A and B.
The resulting matrix, C, will be:
To get the element in the 1st row, 1st column (C11), you take the dot product of A's 1st row and B's 1st column: .
To get the element in the 1st row, 2nd column (C12), you take the dot product of A's 1st row and B's 2nd column: .
I believe that AI was used recently applied to simplify matrix multiplication by reducing the steps required
You're correct! In 2022, researchers at Google's DeepMind successfully used an AI system called AlphaTensor to discover new and more efficient algorithms for matrix multiplication.
This was a significant breakthrough because matrix multiplication is a fundamental operation in nearly all areas of computing, from AI and graphics to weather forecasting.
How It Worked: Turning Math into a Game 🎲
The core idea was to transform the problem of finding a new algorithm into a game that an AI could learn to play.
The "Game Board": The AI was presented with a 3D tensor, which is a mathematical representation of the matrix multiplication problem.
The "Goal": The goal of the game was to "zero out" this tensor by applying a series of allowed mathematical operations.
The "Score": The score was determined by the number of steps (specifically, the number of multiplications) taken to reach the goal.
A lower score meant a more efficient algorithm.
The AI, AlphaTensor, was based on AlphaZero, the same system that mastered complex games like Go and chess.
What AlphaTensor Discovered
AlphaTensor's achievements were remarkable for several reasons:
Rediscovered Human Algorithms: As a baseline, it independently rediscovered historically important algorithms, such as Strassen's method from 1969, proving the system was effective.
Broke Human Records: For the first time in over 50 years, it found algorithms that were demonstrably faster (requiring fewer steps) than the best ones discovered by human mathematicians for specific matrix sizes.
For example, it reduced the number of multiplications for a 4x4 matrix from 49 to 47. Uncovered a Vast New Landscape: The AI didn't just find one new algorithm; it uncovered thousands of new, viable algorithms, showing that the space of possible solutions is much larger than previously thought.
Why It Matters
This work is about more than just speeding up one specific calculation. It represents a new paradigm where AI is used not just to perform a task, but to discover the fundamental algorithms for how tasks are performed. This has profound implications for using AI as a tool to accelerate scientific and mathematical discovery in other complex fields.
Describe how Mathematica supported by Wolfram LLM Tool Kit could be applied to do this
Excellent question. Applying Mathematica with the Wolfram LLM Tool Kit to this problem wouldn't replicate AlphaTensor's raw reinforcement learning approach directly. Instead, it would create a powerful, interactive workflow where the LLM acts as a "research director" or "strategic partner," using Mathematica as its rigorous computational engine.
The LLM wouldn't be the one playing the game billions of times. It's not designed for that kind of high-speed, specialized search. Rather, it would guide the exploration in a more structured, human-like way.
A Potential Workflow: LLM as Research Director
Here’s how a researcher could use this combination to explore for new matrix multiplication algorithms:
1. Problem Formulation (Natural Language to Formal Code)
The process starts with the human researcher giving the LLM a high-level goal in plain English.
Human Prompt: "I want to find more efficient ways to multiply two 2x2 matrices. Represent this problem as a tensor decomposition task in the Wolfram Language and define the rules for a valid algorithm."
LLM Action: The LLM, connected to the Wolfram tools, would generate the precise Mathematica code to:
Construct the 3D tensor that represents matrix multiplication.
Define a function to check if a proposed decomposition is mathematically correct (i.e., if it actually computes matrix multiplication).
Define a "fitness function" to count the number of multiplications in a proposed solution (the metric to be minimized).
2. Hypothesis Generation (Brainstorming "Moves")
Instead of random exploration, the LLM can generate plausible strategies or "moves" based on its vast training data, which includes mathematical papers and programming patterns.
Human Prompt: "Based on Strassen's algorithm, propose a novel first step for decomposing the 2x2 tensor."
LLM Action: The LLM generates a hypothesis and the Wolfram Language code to execute it. For example, it might suggest a specific combination of input matrix elements, translate that into a
TensorContract
orTensorProduct
operation, and pass it to Mathematica.
3. Execution and Verification (Mathematica's Core Strength)
This is where Mathematica does the heavy lifting. It executes the code sent by the LLM.
Mathematica's Role:
It performs the proposed tensor operation.
It uses its symbolic verification capabilities (e.g.,
FullSimplify
orFindEquationalProof
) to rigorously check if the resulting algorithm is still mathematically valid.It calculates the "fitness score" (the number of multiplications) of the current partial or full solution.
It returns the result—
True/False
for validity, the score, and the resulting new tensor—back to the LLM.
4. Iteration and Guided Search (The Feedback Loop)
The LLM receives the structured output from Mathematica and decides what to do next. This creates an interactive loop.
LLM Action:
If the last step was successful, it might say, "The previous step was valid and reduced complexity. Now, let's try to decompose the remaining tensor."
If the step failed, it would recognize this and say, "That approach led to an invalid algorithm. Let's backtrack and try a different combination of terms."
This loop continues, with the LLM proposing strategic paths and Mathematica providing immediate, rigorous feedback.
Division of Labor: Brains and Brawn
This approach creates a powerful symbiosis:
The LLM's Role (The "Brains" 🧠):
Strategy & Intuition: Proposes high-level plans and hypotheses.
Code Generation: Translates natural language goals into executable Wolfram Language code.
Interpretation: Understands the results from Mathematica and plans the next logical step.
Mathematica's Role (The "Brawn" 🦾):
Rigorous Computation: Executes complex tensor manipulations flawlessly.
Absolute Truth: Provides definitive, symbolic proof of whether an algorithm is correct.
Quantification: Calculates the precise cost (fitness score) of any proposed solution.
This method is less about brute-force, black-box discovery like AlphaTensor and more about an AI-assisted, interactive, and interpretable exploration of the mathematical search space.
Would Matlab with any of its numerous available tool kit addons be more useful?
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