handling LetTuple in simplifyPaths

src/main/scala/leon/purescala/TreeOps.scala

@@ -1245,6 +1245,11 @@ object TreeOps {
         val se = rec(e, path)
         Let(i, se, rec(b, Equals(Variable(i), se) +: path))
 
+      case LetTuple(is, e, b) =>
+        // Similar to the Let case
+        val se = rec(e, path)
+        LetTuple(is, se, rec(b, Equals(Tuple(is.map(Variable(_))), se) +: path)) 
+
       case IfExpr(cond, then, elze) =>
         val rc = rec(cond, path)
         rc match {

src/main/scala/leon/purescala/Trees.scala

@@ -83,10 +83,9 @@ object Trees {
 
   case class Tuple(exprs: Seq[Expr]) extends Expr {
     val subTpes = exprs.map(_.getType).map(bestRealType)
-    if(!subTpes.exists(_ == Untyped)) {
+    if(subTpes.forall(_ != Untyped)) {
       setType(TupleType(subTpes))
     }
-
   }
 
   // This must be 1-indexed !