gistfile1.rb

ruby-1.9.3-p0 :001 > def foo
ruby-1.9.3-p0 :002?>   def boo
ruby-1.9.3-p0 :003?>     puts "in boo"
ruby-1.9.3-p0 :004?>     end
ruby-1.9.3-p0 :005?>   puts "in foo"
ruby-1.9.3-p0 :006?>   end
 => nil 
ruby-1.9.3-p0 :007 > foo
in foo
 => nil 
ruby-1.9.3-p0 :008 > def foo
ruby-1.9.3-p0 :009?>   def boo
ruby-1.9.3-p0 :010?>     puts "in boo"
ruby-1.9.3-p0 :011?>     end
ruby-1.9.3-p0 :012?>   puts "in foo"
ruby-1.9.3-p0 :013?>   boo
ruby-1.9.3-p0 :014?>   end
 => nil 
ruby-1.9.3-p0 :015 > foo
in foo
in boo
 => nil 
ruby-1.9.3-p0 :016 > foo.boo
in foo
in boo
in boo
 => nil