... sorry, sent too early

> You can compute the strongly connected components directly on the transitive closure. Notice you don't need to transpose it explicitely

// Strong connected components matrix form

let sccmatrix = function matrix ->

  let n = Array.length matrix in

  let result = Array.make_matrix n n 0 in

  for i = 0 to n - 1 do

      for j = 0 to n - 1 do

          result.(i).(j) <- min matrix.(i).(j) matrix.(j).(i)

      done;

  done; 

  result

Now you just have to collect the results in a list of lists.

You will need to avoid generating multiple times the same component.

// Output list of lists from matrix

let output = function matrix ->

    let n = Array.length matrix in

    let marked = Array.make n false in

    let result = ref [] in

    for i = 0 to n - 1 do

        if (not marked.(i)) then

        begin

            let component = ref [i] in

            for j = i + 1 to n - 1 do

                if matrix.(i).(j) = 1 then

                begin

                     marked.(j) <- true;

                     component := j :: !component

                end

            done;

            result := !component :: !result

         end

     done;     

     !result

Since the code uses for loops, it needs references to store the results.

One can do a nicer code and merge the two functions sccmatrix and output

        Diego Olivier