russian/step1.go
func precededByARinRV(word *snowballword.SnowballWord, suffixLen int) bool {
	idx := len(word.RS) - suffixLen - 1
	if idx >= word.RVstart && (word.RS[idx] == 'а' || word.RS[idx] == 'я') {
		return true
	}
	return false
}
func precededByARinRV(word *snowballword.SnowballWord, suffixLen int) bool {
	idx := len(word.RS) - suffixLen - 1
	if idx >= word.RVstart && (word.RS[idx] == 'а' || word.RS[idx] == 'я') {
		return true
	}
	return false
}
// There are multiple classes of endings that must be
// preceded by а (a) or я (ia) in RV in order to be removed.
//