Adds a very simple rspec style matcher

lib/unification_assertion.rb

@@ -143,3 +143,12 @@ def assert_unifiable(a, b, message = "", options = {}, &block)
   end
 end
 
+if defined?(RSpec)
+  RSpec::Matchers.define :unify do |expected|
+    match do |actual|
+      UnificationAssertion.unify([[actual, expected]]) do |a, b|
+        a.should == b
+      end
+    end
+  end
+end