Weighted Real-Valued Logic Neurons for Interpretable Neural Networks

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Solution Overview

Problem

Artificial neural networks face challenges in interpretable inference and gradient optimization due to their reliance on large training datasets and vulnerability to adversarial attacks, while formal logic systems are computationally intensive and require extensive domain expertise.

Innovation Solution

Implementing a neural network with logical neurons that use weighted real-valued logic gates, where the threshold-of-truth is determined through activation optimization to maximize expressivity and gradient quality, allowing for interpretable and efficient learning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If formal logic systems are used for inference, then interpretability and verifiability are improved, but computational intensity and requirement for domain expert input increase

Engineering Contradiction:
ImproveinterpretabilityVSAvoidcomputational intensity
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent merges formal logic systems with neural networks by integrating logical neurons that perform logical operations (AND, OR, NOT, IMPLIES) within the neural network architecture. This combination allows the system to maintain the interpretability and verifiability of formal logic while leveraging the computational efficiency and parallel processing capabilities of neural networks, thereby reducing overall computational intensity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The logical neurons in the patent serve multiple functions: they perform both logical inference operations and neural network computations. This multi-functionality allows the system to handle both symbolic reasoning and numerical processing within a unified framework, reducing the need for separate domain expert configurations and lowering computational overhead.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If neural networks are used for inference, then computational efficiency and parallel processing are improved, but interpretability and verifiability deteriorate

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidinterpretability
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent combines traditional neural network layers with logical neuron layers that perform interpretable logical operations. This hybrid architecture maintains the computational efficiency and parallel processing capabilities of neural networks while introducing interpretability through the logical operations, allowing the system to provide verifiable reasoning paths.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces visualizable logical states and activation patterns that can be interpreted and verified. By making the internal states of logical neurons observable and interpretable (analogous to color changes providing visual information), the system enables verification of the inference process while maintaining computational efficiency.

Inventive Principle:
Principle #32Color changes

3Manufacturing precision

If activation optimization is performed to maximize expressivity, then logical constraint satisfaction is improved, but gradient quality may deteriorate

Engineering Contradiction:
Improvelogical constraint satisfactionVSAvoidgradient quality
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent optimizes the activation function parameters (such as the threshold parameter alpha) to balance logical constraint satisfaction and gradient quality. By carefully selecting and adjusting these parameters, the system achieves both high expressivity for logical operations and sufficient gradient flow for effective backpropagation and learning.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs dynamic activation functions that can adapt their behavior based on the input context and training phase. This dynamic approach allows the system to satisfy logical constraints when needed while maintaining gradient quality for learning, effectively balancing both requirements through adaptive parameter adjustment during training.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11494634B2Optimizing capacity and learning of weighted real-valued logic
Publication Date: 2022.11.08 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US11494634B2 patent drawing
  • US11494634B2 patent drawing
  • US11494634B2 patent drawing

AI summary

Maximum expressivity can be received representing a ratio between maximum and minimum input weights to a neuron of a neural network implementing a weighted real-valued logic gate. Operator arity can be received associated with the neuron. Logical constraints associated with the weighted real-valued logic gate can be determined in terms of weights associated with inputs to the neuron, a threshold-of-truth, and a neuron threshold for activation. The threshold-of-truth can be determined as a parameter used in an activation function of the neuron, based on solving an activation optimization formulated based on the logical constraints, the activation optimization maximizing a product of expressivity representing a distribution width of input weights to the neuron and gradient quality for the neuron given the operator arity and the maximum expressivity. The neural network of logical neurons can be trained using the activation function at the neuron, the activation function using the determined threshold-of-truth.