---
license: mit
task_categories:
  - text-generation
  - feature-extraction
language:
  - en
tags:
  - theorem-proving
  - formal-methods
  - dafny
  - verification
  - imperative-programming
size_categories:
  - 1K<n<10K
dataset_info:
  features:
  - {name: statement, dtype: string}
  - {name: proof, dtype: string}
  - {name: type, dtype: string}
  - {name: symbolic_name, dtype: string}
  - {name: library, dtype: string}
  - {name: filename, dtype: string}
  - {name: imports, list: string}
  - {name: deps, list: string}
  - {name: docstring, dtype: string}
  - {name: source_url, dtype: string}
  - {name: commit, dtype: string}
  splits:
  - {name: train, num_examples: 23281}
  config_name: default
configs:
- config_name: default
  data_files:
  - split: train
    path: data/train-*
---

# Dafny

A structured dataset of functions, lemmas, and predicates from **Dafny**, a verification-aware programming language.

## Source

- Repository: https://github.com/dafny-lang/dafny
- Commit: `8bb7795048d9252198380dec49ffac1e933e25ae`
- Files: 2155
- License: mit

## Schema

| Column | Type | Description |
|--------|------|-------------|
| statement | string | Declaration signature/claim with the leading keyword removed (verbatim slice); the full declaration minus its proof |
| proof | string | Verbatim proof/body, empty if the declaration has none |
| type | string | Declaration keyword |
| symbolic_name | string | Declaration identifier |
| library | string | Sub-library |
| filename | string | Repository-relative source path |
| imports | list[string] | File-level `Require`/`Import` modules |
| deps | list[string] | Intra-corpus identifiers referenced |
| docstring | string | Preceding documentation comment, empty if absent |
| source_url | string | Upstream repository |
| commit | string | Upstream commit extracted |

## Statistics

- Entries: 23,281
- With proof: 20,098 (86.3%)
- With docstring: 0 (0.0%)
- Libraries: 158

### By type

| Type | Count |
|---|---|
| method | 7,955 |
| function | 4,447 |
| lemma | 2,370 |
| predicate | 1,858 |
| datatype | 1,315 |
| type | 1,201 |
| class | 1,140 |
| const | 1,002 |
| newtype | 772 |
| trait | 501 |
| constructor | 477 |
| codatatype | 124 |
| iterator | 117 |
| copredicate | 1 |
| colemma | 1 |

## Example

```
{:extern "Token"} Token extends object
{
    var val: CsString
    var LeadingTrivia: CsString
    var TrailingTrivia: CsString
    var Next: Token?
    ghost var allTokens: seq<Token>
```

- type: trait | symbolic_name: `Token` | Source/DafnyCore/AST/DafnyInterface.dfy

## Use

Each declaration is split into a `statement` (signature/claim) and a `proof` (body) that are disjoint
and together form the complete declaration, for proof modeling, autoformalization, retrieval, and
dependency analysis via `deps`.

## Citation

```bibtex
@misc{dafny_dataset,
  title  = {Dafny},
  author = {Norton, Charles},
  year   = {2026},
  note   = {Extracted from https://github.com/dafny-lang/dafny, commit 8bb7795048d9},
  url    = {https://huggingface.co/datasets/phanerozoic/Dafny}
}
```