rick@ricks-computer:~% irb
irb(main):001:0> def sum(*nums)
irb(main):002:1>   nums.empty? ? 0 : nums.shift + sum(*nums)
irb(main):003:1> end
=> nil
irb(main):004:0> sum 1,2,3
=> 6
irb(main):005:0> sum *(1..5).to_a
=> 15
irb(main):006:0> sum *(1..10000).to_a
zsh: illegal hardware instruction  irb