Error in infl(model) : could not find function "infl"

The error message suggests that the function "infl" could not be found in the current environment or R package. This could be due to a few reasons:

1. The "infl" function is not installed: Check if the "infl" package is installed in your R environment. If not, you can install it using the following command: `install.packages("infl")`.

2. The "infl" function is not loaded: If the package is installed, but not loaded, you can load it using the following command: `library(infl)`.

3. The "infl" function is not defined in the package: It is also possible that the "infl" function is not defined in the package. In this case, you may want to check the documentation of the package or contact the package maintainer for help.

Once you have resolved the issue, you should be able to use the "infl" function in your R code.