Creating nested procs with inject

nested.rb

inside = Proc.new{ puts 'inside' }

nested = [1,2,3].reverse.inject(inside) do |sum, obj|
 Proc.new do |&inner|
   puts obj
   sum.call(&inner)
   puts obj
 end
end

nested.call() 

output.txt

1
2
3
inside
3
2
1