The rules that use the vocabulary item "bugs" are:
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two
bugs five
bugs four
bugs one
bugs seven
bugs six
bugs three
bugs two