diff --git a/src/orderedsets/Main.scala b/src/orderedsets/Main.scala
index 7cc8895a8d714d4528e0531f22baba5903f72f5a..560245434f57ba41e996af5fe3ed0946e6007a71 100644
--- a/src/orderedsets/Main.scala
+++ b/src/orderedsets/Main.scala
@@ -7,6 +7,9 @@ import purescala.Trees._
 class Main(reporter: Reporter) extends Solver(reporter) {
   val description = "Solver for constraints on ordered sets"
 
+  // checks for V-A-L-I-D-I-T-Y !
+  // Some(true) means formula is valid (negation is unsat)
+  // None means you don't know.
   def solve(expr: Expr) : Option[Boolean] = {
     reporter.info(expr, "I have no idea how to solve this :(")
     None