ref: f1650040b7185326951972b827e64acd655628cb dir: /tests/ListCompr.ref/
[1,2,3] [1,3] [2,3,4] [(1,1),(1,2),(2,1),(2,2),(3,1),(3,2)] [(1,1),(2,1),(2,2),(3,1),(3,2),(3,3)] [1,2,3,1,2,3,4] [[2,3],[3,4],[4,5]] [5,13,103] ["5","def"]