In 'Regression Analysis in R: Adapting to Varied Data Types' the following lines are used to help render the fitted regression model.

However, because of this line:

The resultant rendered line (when using learnr/shiny) will look like this:

Which isn't as expected.
There are two problems here (and another minor one I guess).

First: Line 696 attempts to render a latex expression with an R parser. As a result, you end up with a upwards arrow (for the \f part) and $ signs around the expression.
Second: The = sign is missing after the fraction

Minor: The coefficient of AlcoholUnits and ExerciseHours under this seed are negative, so you end up with + - 0.123, which might be confusing to some readers (as the negative sign is much smaller than the positive sign).