From: Ryan Davis <ryand-ruby@...>
Date: 2010-06-03T07:36:44+09:00
Subject: [ruby-core:30564] 1.9.2 - incorrect warning?

  !   ((a and b) or (c and d))

  not ((a and b) or (c and d))

blah.rb:3: warning: (...) interpreted as grouped expression