> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/c/catamorphism.md).

# Catamorphism

```ruby
say (1..10 -> reduce('+'))
say (1..10 -> reduce{|a,b| a + b})
```