класс Range

# File activesupport/lib/active_support/core_ext/range/overlaps.rb, line 5
def overlaps?(other)
  cover?(other.first) || other.cover?(first)
end

Сравнить два диапазона и определить, перекрываются ли они

(1..5).overlaps?(4..6) # => true
(1..5).overlaps?(7..9) # => false