           puzzle.solve()
 
   eliminate_with_tricky_sets: ->
-    @tricky_sets.some (args) =>
-      [subset, rest_of_set, elimination_set] = args
+    @tricky_sets.some ([subset, rest_of_set, elimination_set]) =>
       subset.flatMap (position) =>
         if position.placed then [] else position.possible
       .uniq().filter (digit) =>

    # setup = File.read(filename).gsub(/#.*/, "").gsub(/\s/, "")
    # end

    setup.split("").zip(@positions).forEach (args) =>
      [c, position] = args
      if c != "-"
        console.log "placing initial #{c} in position #{position.number}"
        position.place(Number(c))

    # single square, then the digit can be eliminated from the other
    # Positions of that square.

    @tricky_sets = rows.concat(cols).product(squares).flatMap ([row, square]) =>
      common = row.positions.intersect(square.positions)
      if !common.is_empty()
        # Each Array in @tricky_sets contains three
