Check cross-references that are repetitive or (in the case of cleveref and varioref) incorrect case.
check_xrefs(filename, permitted.case = c(NA, "upper", "lower"), .report_error)A LaTeX file
One of NA, "upper", "lower". If NA, the default,
both \Cref and \cref are permitted, but not in the same document.
If upper, only \Cref
is permitted; if lower, only \cref.
If NULL, the case is not checked at all.
The function to provide context to the error.