threshold-fulladder

Adds three 1-bit inputs (a, b, carry_in), producing sum and carry_out. The core of ripple-carry adders.

Circuit

        a       b
        │       │
        └───┬───┘
            ▼
       ┌─────────┐
       │   HA1   │  First half adder
       └─────────┘
        │       │
       s1       c1
        │        \
        │    cin  \
        └──┬──┘    \
           ▼        \
      ┌─────────┐    \
      │   HA2   │     │
      └─────────┘     │
       │       │      │
      sum      c2     │
               │      │
               └──┬───┘
                  ▼
              ┌──────┐
              │  OR  │
              └──────┘
                  │
                  ▼
                cout

Truth Table

a	b	cin	sum	cout
0	0	0	0	0
0	0	1	1	0
0	1	0	1	0
0	1	1	0	1
1	0	0	1	0
1	0	1	0	1
1	1	0	0	1
1	1	1	1	1

Binary: a + b + cin = (cout × 2) + sum

Architecture

Component	Neurons
HA1 (a + b)	4
HA2 (s1 + cin)	4
OR (c1, c2)	1

Total: 9 neurons, 21 parameters, 4 layers

Composition

s1, c1 = HalfAdder(a, b)
sum, c2 = HalfAdder(s1, cin)
cout = OR(c1, c2)

A carry propagates if either half adder produces one.

Usage

from safetensors.torch import load_file

w = load_file('model.safetensors')

def full_adder(a, b, cin):
    # Implementation uses two half adders + OR
    # See model.py for full implementation
    pass

Files

threshold-fulladder/
├── model.safetensors
├── model.py
├── config.json
└── README.md

License

MIT