Pantograph/doc/repl.md

REPL

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.

• env.save { "path": <fileName> }, env.load { "path": <fileName> }: Save/Load the current environment to/from a file

• 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

• goal.save { "id": <id>, "path": <fileName> }, goal.load { "path": <fileName> }: Save/Load a goal state to/from a file. The environment is not carried with the state. The user is responsible to ensure the sender/receiver instances share the same environment.

• frontend.process { ["fileName": <fileName>,] ["file": <str>], invocations: <bool>, sorrys: <bool>, newConstants: <bool> }: Executes the Lean frontend on a file, collecting the tactic invocations ("invocations": true), the sorrys and type errors into goal states ("sorrys": true), and new constants ("newConstants": true). In the case of sorrys, this command additionally outputs the position of each captured sorry.

Errors

When an error pertaining to the execution of a command happens, the returning JSON structure is

{ "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.