... 'sass-rails', '˜> 3.2.3'gem 'coffee-rails', '˜> 3.2.2'gem 'uglifier', '>= 1.2.3'endtogroup :assets dogem 'sass-rails', ... 'sass-rails', '3.2.4'gem 'coffee-rails', '3.2.2'gem 'uglifier', '1.2.3'endThe syntaxgem 'uglifier', '>= 1.2.3'installs ... codegem 'coffee-rails', '˜> 3.2.2'installs the gemcoffee-rails(also needed by the asset pipeline) as long as it’s lowerthan version3.3. In other words, the>=notation...