183 lines
6.6 KiB
Markdown
183 lines
6.6 KiB
Markdown
# Pantograph
|
|
|
|
A Machine-to-Machine interaction system for Lean 4.
|
|
|
|
|
|
|
|
Pantograph provides interfaces to execute proofs, construct expressions, and
|
|
examine the symbol list of a Lean project for machine learning.
|
|
|
|
See [documentations][doc/] for design rationale and references.
|
|
|
|
## Installation
|
|
|
|
For Nix users, run
|
|
``` sh
|
|
nix build .#{sharedLib,executable}
|
|
```
|
|
to build either the shared library or executable.
|
|
|
|
Install `elan` and `lake`, and run
|
|
``` sh
|
|
lake build
|
|
```
|
|
This builds the executable in `.lake/build/bin/pantograph-repl`.
|
|
|
|
## Executable Usage
|
|
|
|
``` sh
|
|
pantograph MODULES|LEAN_OPTIONS
|
|
```
|
|
|
|
The REPL loop accepts commands as single-line JSON inputs and outputs either an
|
|
`Error:` (indicating malformed command) or a JSON return value indicating the
|
|
result of a command execution. The command can be passed in one of two formats
|
|
```
|
|
command { ... }
|
|
{ "cmd": command, "payload": ... }
|
|
```
|
|
The list of available commands can be found in `Pantograph/Protocol.lean` and below. An
|
|
empty command aborts the REPL.
|
|
|
|
The `pantograph` executable must be run with a list of modules to import. It can
|
|
also accept lean options of the form `--key=value` e.g. `--pp.raw=true`.
|
|
|
|
Example: (~5k symbols)
|
|
```
|
|
$ pantograph Init
|
|
env.catalog
|
|
env.inspect {"name": "Nat.le_add_left"}
|
|
```
|
|
Example with `mathlib4` (~90k symbols, may stack overflow, see troubleshooting)
|
|
```
|
|
$ pantograph Mathlib.Analysis.Seminorm
|
|
env.catalog
|
|
```
|
|
Example proving a theorem: (alternatively use `goal.start {"copyFrom": "Nat.add_comm"}`) to prime the proof
|
|
```
|
|
$ pantograph Init
|
|
goal.start {"expr": "∀ (n m : Nat), n + m = m + n"}
|
|
goal.tactic {"stateId": 0, "goalId": 0, "tactic": "intro n m"}
|
|
goal.tactic {"stateId": 1, "goalId": 0, "tactic": "assumption"}
|
|
goal.delete {"stateIds": [0]}
|
|
stat {}
|
|
goal.tactic {"stateId": 1, "goalId": 0, "tactic": "rw [Nat.add_comm]"}
|
|
stat
|
|
```
|
|
where the application of `assumption` should lead to a failure.
|
|
|
|
### Commands
|
|
|
|
See `Pantograph/Protocol.lean` for a description of the parameters and return values in JSON.
|
|
* `reset`: Delete all cached expressions and proof trees
|
|
* `stat`: Display resource usage
|
|
* `expr.echo {"expr": <expr>, "type": <optional expected type>, ["levels": [<levels>]]}`: Determine the
|
|
type of an expression and format it.
|
|
* `env.catalog`: Display a list of all safe Lean symbols in the current environment
|
|
* `env.inspect {"name": <name>, "value": <bool>}`: Show the type and package of a
|
|
given symbol; If value flag is set, the value is printed or hidden. By default
|
|
only the values of definitions are printed.
|
|
* `options.set { key: value, ... }`: Set one or more options (not Lean options; those
|
|
have to be set via command line arguments.), for options, see `Pantograph/Protocol.lean`
|
|
|
|
One particular option for interest for machine learning researchers is the
|
|
automatic mode (flag: `"automaticMode"`). By default it is turned on, with
|
|
all goals automatically resuming. This makes Pantograph act like a gym,
|
|
with no resumption necessary to manage your goals.
|
|
* `options.print`: Display the current set of options
|
|
* `goal.start {["name": <name>], ["expr": <expr>], ["levels": [<levels>]], ["copyFrom": <symbol>]}`:
|
|
Start a new proof from a given expression or symbol
|
|
* `goal.tactic {"stateId": <id>, "goalId": <id>, ...}`: Execute a tactic string on a
|
|
given goal. The tactic is supplied as additional key-value pairs in one of the following formats:
|
|
- `{ "tactic": <tactic> }`: Execute an ordinary tactic
|
|
- `{ "expr": <expr> }`: Assign the given proof term to the current goal
|
|
- `{ "have": <expr>, "binderName": <name> }`: Execute `have` and creates a branch goal
|
|
- `{ "calc": <expr> }`: Execute one step of a `calc` tactic. Each step must
|
|
be of the form `lhs op rhs`. An `lhs` of `_` indicates that it should be set
|
|
to the previous `rhs`.
|
|
- `{ "conv": <bool> }`: Enter or exit conversion tactic mode. In the case of
|
|
exit, the goal id is ignored.
|
|
* `goal.continue {"stateId": <id>, ["branch": <id>], ["goals": <names>]}`:
|
|
Execute continuation/resumption
|
|
- `{ "branch": <id> }`: Continue on branch state. The current state must have no goals.
|
|
- `{ "goals": <names> }`: Resume the given goals
|
|
* `goal.remove {"stateIds": [<id>]}"`: Drop the goal states specified in the list
|
|
* `goal.print {"stateId": <id>}"`: Print a goal state
|
|
* `frontend.process { ["fileName": <fileName>",] ["file": <str>], invocations:
|
|
<bool>, sorrys: <bool> }`: Executes the Lean frontend on a file, collecting
|
|
either the tactic invocations (`"invocations": true`) or the sorrys into goal
|
|
states (`"sorrys": true`)
|
|
|
|
### Errors
|
|
|
|
When an error pertaining to the execution of a command happens, the returning JSON structure is
|
|
|
|
``` json
|
|
{ "error": "type", "desc": "description" }
|
|
```
|
|
Common error forms:
|
|
* `command`: Indicates malformed command structure which results from either
|
|
invalid command or a malformed JSON structure that cannot be fed to an
|
|
individual command.
|
|
* `index`: Indicates an invariant maintained by the output of one command and
|
|
input of another is broken. For example, attempting to query a symbol not
|
|
existing in the library or indexing into a non-existent proof state.
|
|
|
|
### Project Environment
|
|
|
|
To use Pantograph in a project environment, setup the `LEAN_PATH` environment
|
|
variable so it contains the library path of lean libraries. The libraries must
|
|
be built in advance. For example, if `mathlib4` is stored at `../lib/mathlib4`,
|
|
the environment might be setup like this:
|
|
|
|
``` sh
|
|
LIB="../lib"
|
|
LIB_MATHLIB="$LIB/mathlib4/lake-packages"
|
|
export LEAN_PATH="$LIB/mathlib4/build/lib:$LIB_MATHLIB/aesop/build/lib:$LIB_MATHLIB/Qq/build/lib:$LIB_MATHLIB/std/build/lib"
|
|
|
|
LEAN_PATH=$LEAN_PATH build/bin/pantograph $@
|
|
```
|
|
The `$LEAN_PATH` executable of any project can be extracted by
|
|
``` sh
|
|
lake env printenv LEAN_PATH
|
|
```
|
|
|
|
### Troubleshooting
|
|
|
|
If lean encounters stack overflow problems when printing catalog, execute this before running lean:
|
|
```sh
|
|
ulimit -s unlimited
|
|
```
|
|
|
|
## Library Usage
|
|
|
|
`Pantograph/Library.lean` exposes a series of interfaces which allow FFI call
|
|
with `Pantograph` which mirrors the REPL commands above. It is recommended to
|
|
call Pantograph via this FFI since it provides a tremendous speed up.
|
|
|
|
The executable can be used as-is, but linking against the shared library
|
|
requires the presence of `lean-all`. Note that there isn't a 1-1 correspondence
|
|
between executable (REPL) commands and library functions.
|
|
|
|
Inject any project path via the `pantograph_init_search` function.
|
|
|
|
## Developing
|
|
|
|
A Lean development shell is provided in the Nix flake.
|
|
|
|
### Testing
|
|
|
|
The tests are based on `LSpec`. To run tests, use either
|
|
``` sh
|
|
nix flake check
|
|
```
|
|
or
|
|
``` sh
|
|
lake test
|
|
```
|
|
You can run an individual test by specifying a prefix
|
|
|
|
``` sh
|
|
lake test -- "Tactic/No Confuse"
|
|
```
|