Problem Statement

A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name. Some attributes of a list comprehension are:

Write a list comprehension that builds the list of all Pythagorean triples with elements between   1   and   n. If the language has multiple ways for expressing such a construct (for example, direct list comprehensions and generators), write one example for each.

Let's start with the solution:

{1, 2, 3, 4} → a
seq(a[i]^2, i, 1, dim(a))

seq(x^2, x, 1, 4)