1.8 KiB
Pantograph
An interaction system for Lean 4.
Installation
Install elan and lean4. Then, execute
lake build
In order to use mathlib, its binary must also be built
lake build Qq
lake build aesop
lake build std
lake build mathlib
Usage
The binary must be run inside a lake env environment. i.e. lake env build/bin/pantograph. 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/Commands.lean. An
empty command aborts the REPL.
The Pantograph executable must be run with a list of modules to import.
Example: (~5k symbols)
$ lake env build/bin/Pantograph "Init"
catalog
inspect {"name": "Nat.le_add_left"}
Example with mathlib (~90k symbols)
$ lake env build/bin/Pantograph "Mathlib.Analysis.Seminorm"
catalog
Example proving a theorem: (alternatively use proof.start {"copyFrom": "Nat.add_comm"}) to prime the proof
$ lake env build/bin/Pantograph "Init"
proof.start {"expr": "∀ (n m : Nat), n + m = m + n"}
proof.tactic {"treeId": 0, "stateId": 0, "goalId": 0, "tactic": "intro n m"}
proof.tactic {"treeId": 0, "stateId": 1, "goalId": 0, "tactic": "assumption"}
proof.printTree {"treeId": 0}
proof.tactic {"treeId": 0, "stateId": 1, "goalId": 0, "tactic": "rw [Nat.add_comm]"}
proof.printTree {"treeId": 0}
where the application of assumption should lead to a failure.
Troubleshooting
If lean encounters stack overflow problems when printing catalog, execute this before running lean:
ulimit -s unlimited
Testing
The tests are based on LSpec. To run tests,
test/all.sh