Flix – Safe, reliable, concise, and functional-first programming language(flix.dev)

    // Given an edge x -> y, there is a path x -> y.
    path(x, y) :- edge(x, y).

    // Given an edge x -> z and a path z -> y, there is a path x -> y.
    path(x, y) :- edge(x, y: z), path(x: z, y).

    WITH RECURSIVE path(x, y) AS (
      SELECT
        edge.x AS x,
        edge.y AS y
      FROM
        edge
      UNION
      SELECT
        edge.x AS x,
        path.y AS y
      FROM
        edge,
        path
      WHERE
        edge.y = path.x
    )
    SELECT
      DISTINCT *
    FROM
      path