Specifying the range of supported Rails versions in a project

The config/environment.rb of my rails project contains this line:

RAILS_GEM_VERSION = '>= 2.3.2' unless defined? RAILS_GEM_VERSION

Which makes sure that only Rails开发者_StackOverflow中文版 of version 2.3.2 or greater will be used to run this app.

Is there a way of specifying both the lower and the upper boundary at the same time? So that it would run, say, only on versions higher than 2.3.1 and lower than 2.3.6?

I dug around in Rails and Rubygems source for about an hour, and I'm sorry but I can't say exept to give it a go! Install a few rails versions and then see what happens!