disprove

Attempt to disprove theorems by proving the negation.

Input Parameters

content · str · required · Lean source code

The Lean source code to be processed by this tool.

names · list[str] · Theorem names to process

Optional list of theorem names to process. If not specified, all theorems are processed. Requesting a name not found in the code returns an error. When theorems_only is false, these select over all declarations (not just theorems).

indices · list[int] · Theorem indices to process

Optional list of theorem indices to process (0-based). Supports negative indices: -1 is the last theorem, -2 is second-to-last, etc. If not specified, all theorems are processed. When theorems_only is false, these select over all declarations (not just theorems).

terminal_tactics · list[str] · default: ['grind'] · Tactics to try when attempting to disprove

Tactics tried in order to prove the negation. grind often works for false statements. Defaults to 'grind'.

theorems_only · bool · default: True · Process theorems/lemmas only

If true (default), only theorem/lemma declarations are processed. Set to false to process all declaration kinds (def/instance/abbrev/opaque/etc). When false, names and indices select over all declarations rather than just theorems.

Note: on this tool, operations on non-theorem kinds are a no-op.

verbosity · float · default: 0 · Pretty-printer verbosity level (0-2)

0=default, 1=robust, 2=extra robust. Higher levels produce more explicit type annotations. Use when default output has ambiguity errors.

ignore_imports · bool · default: True · Ignore import mismatches

Controls import statement handling:

• true (default): Ignore the imports in content and substitute the environment's default header. This uses the pre-built cached environment, so it is fast. The substituted code is returned in the content field.
• false: Process the imports in content exactly as written. This is significantly slower (the cached environment cannot be reused) and may produce inconsistent or incorrect results if a required dependency such as Mathlib.Tactic is missing. A warning is returned in these cases. See the troubleshooting page for more details.

environment · str · required · Lean environment or version

The Lean environment to use for evaluation. Each environment includes a specific Lean version and pre-built dependencies (typically Mathlib).

Available environments: lean-4.28.0, lean-4.27.0, lean-4.26.0, etc.

timeout_seconds · float · default: 120 · Max execution time in seconds

Maximum execution time in seconds. Requests exceeding this limit return a timeout error. Note that end-to-end request latency may exceed this timeout due to queue time and other overhead. Additionally, all non-admin requests are subject to an absolute maximum timeout of 900 seconds (15 minutes).

Output Fields

content · string · Processed Lean code

The Lean code that was actually processed. May differ from input if ignore_imports=true caused header injection.

lean_messages · dict · Messages from Lean compiler

Messages from the Lean compiler with errors, warnings, and infos lists. Errors here indicate invalid Lean code (syntax errors, type errors, etc.); an empty errors list means the code compiles.

If the tool allows declaration selection and a names/indices selection is given, elaboration is skipped for the proofs of unselected declarations, so this field reflects only the selected declarations and is otherwise incomplete.

tool_messages · dict · Messages from disprove tool

Messages from the disprove tool with errors, warnings, and infos lists. Errors here indicate tool-specific issues (not Lean compilation errors).

results · dict · Map from theorem name to disprove result

Each theorem maps to a string indicating the outcome of the disprove attempt.

negated · dict · Map from theorem name to negated goal

Each theorem maps to the negated goal type that was attempted (the statement whose proof would disprove the theorem).

disproved_theorems · list · List of theorems that were disproved

List of theorems that were disproved

timings · dict · Execution timing breakdown

Timing information in milliseconds for various stages of processing.