>>>>> "B" == Brian Candler <B.Candler / pobox.com> writes: B> Which implementation of 'inject' are you using? The one in PragProg requires B> an initial value to be passed as a parameter. svg% cat b.rb #!/usr/bin/ruby -v module Enumerable def ordered? inject { | last, item | return false unless last < item; item } true end end p [1,2,3,1].ordered? p [1,2,3].ordered? svg% svg% b.rb ruby 1.8.0 (2003-07-18) [i686-linux] false true svg% Guy Decoux