2012/9/14 pingon begand <sbronfion@xxxxxxxxx>: > Great comparison. What does || mean in your code? Well, the || is actually the only extension that GSL Shell add to the Lua language, the short function syntax: http://www.nongnu.org/gsl-shell/doc/intro.html#short-func-notation With this syntax you can write something like: |x, y| x + y which is equivalent to the Lua syntax: function(x, y) return x + y end So, the expression '|| fib(20)' for example is an anonymous function that takes no arguments and returns fib(20). Francesco