diff --git a/src/main/scala/fhetest/Checker/Utils.scala b/src/main/scala/fhetest/Checker/Utils.scala
index 26762ef..4d6f183 100644
--- a/src/main/scala/fhetest/Checker/Utils.scala
+++ b/src/main/scala/fhetest/Checker/Utils.scala
@@ -16,6 +16,14 @@ import java.io.{File, PrintWriter}
 import java.nio.file.{Files, Path, Paths, StandardCopyOption}
 
 case class Failure(library: String, failedResult: String)
+
+trait ResultInfo {
+  val programId: Int
+  val program: T2Program
+  val result: String
+  val SEAL: String
+  val OpenFHE: String
+}
 case class ResultValidInfo(
   programId: Int,
   program: T2Program,
@@ -24,7 +32,7 @@ case class ResultValidInfo(
   expected: String,
   SEAL: String,
   OpenFHE: String,
-)
+) extends ResultInfo
 case class ResultInvalidInfo(
   programId: Int,
   program: T2Program,
@@ -33,7 +41,7 @@ case class ResultInvalidInfo(
   invalidFilters: List[String],
   SEAL: String,
   OpenFHE: String,
-)
+) extends ResultInfo
 
 // Define en/decoders using Circe
 // Scheme
@@ -277,10 +285,12 @@ object DumpUtil {
     }
   }
 
-  def readResult(filePath: String): ResultValidInfo = {
+  def readResult(filePath: String): ResultInfo = {
     val fileContents = readFile(filePath)
-    val resultValidInfo = decode[ResultValidInfo](fileContents)
-    resultValidInfo match {
+    val resultInfo =
+      if (filePath contains "invalid") decode[ResultInvalidInfo](fileContents)
+      else decode[ResultValidInfo](fileContents)
+    resultInfo match {
       case Right(info) => info
       case Left(error) => throw new Exception(s"Error: $error")
     }
diff --git a/src/main/scala/fhetest/Command.scala b/src/main/scala/fhetest/Command.scala
index 1cc6dd2..a531680 100644
--- a/src/main/scala/fhetest/Command.scala
+++ b/src/main/scala/fhetest/Command.scala
@@ -257,7 +257,8 @@ case object CmdTest extends BackendCommand("test") {
 }
 
 case object CmdReplay extends Command("replay") {
-  val help = "Replay the given json."
+  val help =
+    "Replay the given json with specified backend (default: interpreter)."
   val examples = List(
     "fhetest replay -fromjson:logs/test/success/2.json",
     "fhetest replay -fromjson:logs/test/success/2.json -b:OpenFHE",
diff --git a/src/main/scala/fhetest/Generate/ValidFilter.scala b/src/main/scala/fhetest/Generate/ValidFilter.scala
index 6edb326..b62968e 100644
--- a/src/main/scala/fhetest/Generate/ValidFilter.scala
+++ b/src/main/scala/fhetest/Generate/ValidFilter.scala
@@ -15,6 +15,7 @@ import fhetest.Utils.*
 // 	FilterLenIsLessThanRingDim,
 // 	FilterModSizeIsBeteween14And60bits,
 // 	FilterMulDepthIsEnough,
+//  FilterMulDepthIsNotNegative,
 // 	FilterOpenFHEBFVModuli,
 // 	FilterPlainModEnableBatching, /* commented */
 // 	FilterPlainModIsPositive, /* commented */
@@ -61,6 +62,32 @@ object ValidFilter {
       )
   }
 
+  case class FilterMulDepthIsNotNegative(
+    prev: LibConfigDomain,
+    validFilter: Boolean,
+  ) extends ValidFilter(prev, validFilter) {
+    def getFilteredLibConfigDomain(): LibConfigDomain =
+      LibConfigDomain(
+        scheme = prev.scheme,
+        ringDim = prev.ringDim,
+        mulDepth =
+          if (validFilter)
+            (realMulDepth => (prev.mulDepth)(realMulDepth).filter(_ >= 0))
+          else
+            (realMulDepth => (prev.mulDepth)(realMulDepth).filterNot(_ >= 0)),
+        plainMod = prev.plainMod,
+        firstModSize = prev.firstModSize,
+        scalingModSize = prev.scalingModSize,
+        securityLevel = prev.securityLevel,
+        scalingTechnique = prev.scalingTechnique,
+        lenMin = prev.lenMin,
+        lenMax = prev.lenMax,
+        boundMin = prev.boundMin,
+        boundMax = prev.boundMax,
+        rotateBound = prev.rotateBound,
+      )
+  }
+
   // TODO: There are 2 options for this implementation
   // * Current implementation filters scalingModSize which is not greater than firstModSize
   // * Another option is to filter firstModSize to be not smaller than scalingModeSize