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:

pyth(N) = [[A,B,C] : A in 1..N, B in A..N, C in B..N, A**2 + B**2 == C**2].

pyth(N) = {{A,B,C} : A in 1..N, B in A..N, C in B..N, A**2 + B**2 == C**2}.

pyth(N) = findall([A,B,C], (member(A,1..N), member(B,1..N), member(C,1..N), A < B, A**2 + B**2 == C**2)).