Bool elem(a val, [a] list, Bool(a, a) eq=equal)
Arguments
val: The value to search for ("needle")list: The list to search ("haystack")eq: Optionally, the function used to check for presence (the default is equal, obviously, but identical might be used)
Usage
Check whether the "needle" occurs at least once in the "haystack". This function can be thought of as a specialised version of any
