threshold-atmost2outof3

At most 2 of 3 inputs high. Equivalent to 3-input NAND gate.

Function

atmost2outof3(a, b, c) = 1 if (a + b + c) <= 2, else 0

Equivalently: NAND(a, b, c) = NOT(a AND b AND c)

Truth Table

a	b	c	sum	out
0	0	0	0	1
0	0	1	1	1
0	1	0	1	1
0	1	1	2	1
1	0	0	1	1
1	0	1	2	1
1	1	0	2	1
1	1	1	3	0

Architecture

Single neuron: weights [-1, -1, -1], bias 2

Fires when: -a - b - c + 2 >= 0, i.e., sum <= 2

Parameters

Inputs	3
Outputs	1
Neurons	1
Layers	1
Parameters	4
Magnitude	5

Usage

from safetensors.torch import load_file
import torch

w = load_file('model.safetensors')

def atmost2of3(a, b, c):
    inp = torch.tensor([float(a), float(b), float(c)])
    return int((inp @ w['neuron.weight'].T + w['neuron.bias'] >= 0).item())

print(atmost2of3(1, 1, 0))  # 1 (sum=2)
print(atmost2of3(1, 1, 1))  # 0 (sum=3)

License

MIT