File size: 2,568 Bytes
1e84f0c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
---

license: mit
tags:
- formal-verification
- coq
- threshold-logic
- neuromorphic
- modular-arithmetic
---


# tiny-mod10-verified

Formally verified MOD-10 circuit. Single-layer threshold network computing modulo-10 arithmetic with 100% accuracy.

## Architecture

| Component | Value |
|-----------|-------|
| Inputs | 8 |
| Outputs | 1 (per residue class) |
| Neurons | 10 (one per residue 0-9) |
| Parameters | 90 (10 × 9) |
| Weights | [1, 1, 1, 1, 1, 1, 1, 1] |
| Bias | 0 |
| Activation | Heaviside step |

## Key Properties

- 100% accuracy (256/256 inputs correct)
- Coq-proven correctness
- All-ones weight pattern (m > input width)
- Computes Hamming weight mod 10
- Compatible with neuromorphic hardware

## Algebraic Pattern

MOD-10 uses all-ones weights because the reset position (position 10) is beyond the 8-bit input width:
- All positions 1-8: weight = 1
- Position 10 (beyond input): would be weight = 1-10 = -9

The circuit tracks cumulative sum mod 10 using the Hamming weight directly.

## Usage

```python

import torch

from safetensors.torch import load_file



weights = load_file('mod10.safetensors')



def mod10_circuit(bits):

    # bits: list of 8 binary values

    inputs = torch.tensor([float(b) for b in bits])

    weighted_sum = (inputs * weights['weight']).sum() + weights['bias']

    return int(weighted_sum.item()) % 10



# Test

print(mod10_circuit([1,1,1,1,1,1,1,1]))  # 8 mod 10 = 8

print(mod10_circuit([0,0,0,0,0,0,0,0]))  # 0 mod 10 = 0

```

## Verification

**Coq Theorem**:
```coq

Theorem mod10_correct_residue_0 : forall x0 x1 x2 x3 x4 x5 x6 x7,

  mod10_is_zero [x0; x1; x2; x3; x4; x5; x6; x7] =

  Z.eqb ((Z.of_nat (hamming_weight [x0; x1; x2; x3; x4; x5; x6; x7])) mod 10) 0.

```

Proven axiom-free using algebraic weight patterns.

Full proof: [coq-circuits/Modular/Mod10.v](https://github.com/CharlesCNorton/coq-circuits/blob/main/coq/Modular/Mod10.v)

## Residue Distribution

For 8-bit inputs (256 total), limited to residues 0-8:
- Residue 0: 1 inputs
- Residue 1: 8 inputs
- Residue 2: 28 inputs
- Residue 3: 56 inputs
- Residue 4: 70 inputs
- Residue 5: 56 inputs
- Residue 6: 28 inputs
- Residue 7: 8 inputs
- Residue 8: 1 inputs
- Residue 9: 0 inputs (unreachable with 8-bit input)

## Citation

```bibtex

@software{tiny_mod10_verified_2025,

  title={tiny-mod10-verified: Formally Verified MOD-10 Circuit},

  author={Norton, Charles},

  url={https://huggingface.co/phanerozoic/tiny-mod10-verified},

  year={2025}

}

```