Function to check if an element belongs to a category according to a thesaurus. It is similar to %in% and is.element, returning a logical vector indicating if each element in a given vector is included in a given set. But InCategory checks for equality assuming the equivalencies defined in the given thesaurus.

InCategory(x, category, thesaurus)

## Arguments

x Character vector to be checked for its inclusion in the category. Character vector identifying the categories in which the inclusion of x will be checked. Each category can be identified by any equivalent name in the thesaurus. A thesaurus object.

## Value

A logical vector of the same length as x. Each value answers the question: Does the corresponding element in x belongs to any of the thesaurus categories identified by category?

zoologThesaurus, %in%
InCategory(c("sheep", "cattle", "goat", "red deer"),