threshold-and4 / model.py
CharlesCNorton
Initial commit: 4-input AND threshold gate
dbaf9f3
"""
Threshold Network for 4-input AND Gate
A formally verified single-neuron threshold network computing 4-way logical conjunction.
Weights are integer-constrained and activation uses the Heaviside step function.
"""
import torch
from safetensors.torch import load_file
class ThresholdAND4:
"""
4-input AND gate implemented as a threshold neuron.
Circuit: output = (w1*x1 + w2*x2 + w3*x3 + w4*x4 + bias >= 0)
With weights=[1,1,1,1], bias=-4: only (1,1,1,1) reaches threshold.
"""
def __init__(self, weights_dict):
self.weight = weights_dict['weight']
self.bias = weights_dict['bias']
def __call__(self, x1, x2, x3, x4):
inputs = torch.tensor([float(x1), float(x2), float(x3), float(x4)])
weighted_sum = (inputs * self.weight).sum() + self.bias
return (weighted_sum >= 0).float()
@classmethod
def from_safetensors(cls, path="model.safetensors"):
return cls(load_file(path))
def forward(x, weights):
"""
Forward pass with Heaviside activation.
Args:
x: Input tensor of shape [..., 4]
weights: Dict with 'weight' and 'bias' tensors
Returns:
AND(x[0], x[1], x[2], x[3])
"""
x = torch.as_tensor(x, dtype=torch.float32)
weighted_sum = (x * weights['weight']).sum(dim=-1) + weights['bias']
return (weighted_sum >= 0).float()
if __name__ == "__main__":
weights = load_file("model.safetensors")
model = ThresholdAND4(weights)
print("4-input AND Gate Truth Table:")
print("-" * 35)
correct = 0
for x1 in [0, 1]:
for x2 in [0, 1]:
for x3 in [0, 1]:
for x4 in [0, 1]:
out = int(model(x1, x2, x3, x4).item())
expected = x1 & x2 & x3 & x4
status = "OK" if out == expected else "FAIL"
if out == expected:
correct += 1
print(f"AND4({x1}, {x2}, {x3}, {x4}) = {out} [{status}]")
print(f"\nTotal: {correct}/16 correct")