gistfile1.rb

require 'rubygems'

v1 = Gem::Version.new('1.8.4')
v2 = Gem::Version.new('1.8.6')
v3 = Gem::Version.new('1.8.7')
v4 = Gem::Version.new('1.9.1')

d0 = Gem::Requirement.new('~> 1.8.0')
d1 = Gem::Requirement.new('~> 1.8.6')
d2 = Gem::Requirement.new('~> 1.8.7')
d3 = Gem::Requirement.new('~> 1.9.1')

[d0, d1, d2, d3].each do |req|
  [v1, v2, v3, v4].each do |ver|
    puts "#{ver} satisfy #{req}? #=> #{req.satisfied_by?(ver)}"
  end
end

gistfile2.txt

Luis@KEORE (D:\Users\Luis\Desktop)
$ ruby t.rb
1.8.4 satisfy ~> 1.8.0? #=> true
1.8.6 satisfy ~> 1.8.0? #=> true
1.8.7 satisfy ~> 1.8.0? #=> true
1.9.1 satisfy ~> 1.8.0? #=> false
1.8.4 satisfy ~> 1.8.6? #=> false
1.8.6 satisfy ~> 1.8.6? #=> true
1.8.7 satisfy ~> 1.8.6? #=> true
1.9.1 satisfy ~> 1.8.6? #=> false
1.8.4 satisfy ~> 1.8.7? #=> false
1.8.6 satisfy ~> 1.8.7? #=> false
1.8.7 satisfy ~> 1.8.7? #=> true
1.9.1 satisfy ~> 1.8.7? #=> false
1.8.4 satisfy ~> 1.9.1? #=> false
1.8.6 satisfy ~> 1.9.1? #=> false
1.8.7 satisfy ~> 1.9.1? #=> false
1.9.1 satisfy ~> 1.9.1? #=> true