The product
Prove your models in the browser.
A notebook for quantitative finance. Write a pricing or risk model, run it, and prove the properties it must hold. An outside solver checks proof-eligible properties, C Note labels sampled results as validation, and a disproved property carries the input that broke it.
Workflow
Authoring
Start blank, from a formula in a paper, or from a request to the assistant, which proposes the model as a change you read and accept. Then the loop is short: run it, prove the properties that matter, and revise. A share link is a read-only snapshot of the source, the result, and the evidence behind it.
Verification
Proof
The strongest results are machine-checked proofs. An SMT solver discharges the property over the real numbers under its stated hypotheses, with no sampling and no contract. The panel names the exact statement it proved and the code it references.
The solver is independent. When a model and its checks come from the same hand, a wrong assumption can pass, because the test inherits the mistake. C Note hands the property to an outside solver and reports the method behind every verdict. When it cannot prove something, it says so and marks the result sampled.
Boundaries
Breaks
A disproved property carries the input that broke it, replayed at machine precision to confirm the break is real and not a rounding artifact. On a validity-region plot the witness is a single marked point, so you see where the model holds and where it stops.
Get started
Access
C Note runs in the browser with a self-serve account. Verify your email and you can run models, prove properties, and work with the assistant, within daily usage limits. To run it inside your own environment, where your models and positions already live, talk to us.