Vero Source Dafny

What it does

When your agent uses it

• Tasks that involve Translation

Example prompts

• “/vero-source-dafny”

Requirements

• Pre-approved tools (allowed-tools): Read, Write, Edit, Bash, Grep, Glob

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

1. 1Ledger struct in Impl foundation file (no markers).
2. 2Valid is vocabulary — Spec helper def valid : Ledger → Prop if
3. 3Deposit → API reference implementation with code markers.
4. 4requires Valid() + ensures Valid() → one

What it can do on your machine

Read from SKILL.md and the folder at commit 0a7325d. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Edit
  • Bash
  • Grep
  • Glob

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are dafny, json and lean).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Vero Source Dafny loads about 2k tokens when it runs. Until then it costs about 94 tokens; SKILL.md has 680 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~94

When it runs · the whole SKILL.md, loaded when a task matches

~2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Read, Write, Edit, Bash, Grep, Glob

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from sunblaze-ucb/vero at commit 0a7325d, republished under its Apache-2.0 licence (© sunblaze-ucb). 680 words, ~2,047 tokens.

name

vero-source-dafny

description

Load BEFORE translating Dafny source to Lean 4. Provides Dafny-specific classification rules, type mappings, and patterns for mapping Dafny constructs (method / function / predicate / lemma / datatype / class) into the ratified bundle paradigm (Impl/ + Spec/ + Bundle + Harness). Pair with vero-discover, vero-plan, vero-translate, and vero-dafny-pitfalls.

allowed-tools

Read, Write, Edit, Bash, Grep, Glob

method CreateAccount(id: int, ledger: Ledger) returns (r: Ledger)
    requires /* … */
    ensures /* post */
{ /* impl */ }

{
  "upstream_name": "CreateAccount",
  "lean_name": "createAccount",
  "sig_abbrev": "CreateAccountSig",
  "lean_type": "AccountId → Ledger → Ledger",
  "opaque": false,
  "nl_description": "Add a new account with the given id to the ledger."
}

namespace Bank
abbrev CreateAccountSig := AccountId → Ledger → Ledger
end Bank

-- !benchmark @start code_aux def=createAccount
-- !benchmark @end code_aux def=createAccount

-- !curation @review v1 [ ] createAccount — Impl/Account, code, reference impl
def Bank.createAccount : Bank.CreateAccountSig :=
-- !benchmark @start code def=createAccount
  -- translated Dafny body, not `sorry`
  ...
-- !benchmark @end code def=createAccount

method Deposit(id: int, amt: nat, l: Ledger) returns (r: Option<Ledger>)
    ensures r.Some? ==> Sum(r.value) == Sum(l) + amt

{
  "name": "spec_deposit_preserves_sum",
  "nl_description": "After a successful deposit, the total equals the previous total plus the amount.",
  "lean_form": "∀ (id : AccountId) (amt : Balance) (l : Ledger) (l' : Ledger), impl.bankLedger.deposit id amt l = some l' → impl.bankLedger.totalAssets l' = impl.bankLedger.totalAssets l + amt",
  "apis_referenced": ["deposit", "totalAssets"],
  "curator_intended_truth": "prove"
}

/-- After a successful deposit, the total equals the previous total plus the amount. -/
def spec_deposit_preserves_sum (impl : RepoImpl) : Prop :=
  ∀ (id : AccountId) (amt : Balance) (l : Ledger) (l' : Ledger),
    impl.bankLedger.deposit id amt l = some l' →
    impl.bankLedger.totalAssets l' = impl.bankLedger.totalAssets l + amt

lemma DepositCommutes(a b: Value, l: Ledger)
    ensures Deposit(a, Deposit(b, l).value) == Deposit(b, Deposit(a, l).value)

class Ledger {
  var accounts: seq<Account>;
  predicate Valid() { NoDuplicateIds(accounts) }
  method Deposit(id, amt) requires Valid() ensures Valid() { … }
}

© sunblaze-ucb, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .claude/skills/vero-source-dafny of sunblaze-ucb/vero.

Open the folder on GitHubat commit 0a7325d