Vale on/off comments don't work with displayed equation

[datawookie]

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Environment

Ubuntu 23.04
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Hi!

Firstly, thanks for the work on Vale. I'm using it with my blog and it has helped me to identify countless errors in my prose. 🙏

I have come upon something puzzling. In a Markdown file I have the following:

<!-- vale off -->
Consider some time series data consisting of \\(n\\) points, \\(y_t = x_t + \epsilon_t\\), where \\(x_t\\) is a smooth signal, \\(\epsilon_t\\) is noise and \\(y_t\\) is the combined noisy sign. If we have observations of \\(y_t\\), how can get back to an estimate of \\(x_t\\)?
<!-- vale on -->

$$\frac{1}{2} \sum\_{t=1}^n (y\_t - x\_t)^2 + \lambda \sum\_{t=2}^{n-1} (x\_{t-1} - 2 x\_t + x\_{t+1})^2.$$

In this case the on/off comments don't work and the spelling of x_t and y_t is highlighted.

If, however, I remove the displayed equation (as below) then the comments work fine.

<!-- vale off -->
Consider some time series data consisting of \\(n\\) points, \\(y_t = x_t + \epsilon_t\\), where \\(x_t\\) is a smooth signal, \\(\epsilon_t\\) is noise and \\(y_t\\) is the combined noisy sign. If we have observations of \\(y_t\\), how can get back to an estimate of \\(x_t\\)?
<!-- vale on -->

Thanks, Andrew.