(documentationinitialPartEnglishLanguage "Every instance of the first argument is initially found as part of an instance of the second argument, even though it might lose that part later in its lifetime. While the part must initially exist as part of a whole, this does not say that each whole necessarily initially contains such a part. For example, a thumb must at some time have been part of a hand, but every hand need not have a thumb, even at birth. This is a class-level relation roughly corresponding to part.")