diff --git a/StgSharp.RegularAnalysis/Text/RegexIR.cs b/StgSharp.RegularAnalysis/Text/RegexIR.cs
index 4bcf2fec..3cf6e270 100644
--- a/StgSharp.RegularAnalysis/Text/RegexIR.cs
+++ b/StgSharp.RegularAnalysis/Text/RegexIR.cs
@@ -55,6 +55,19 @@ namespace StgSharp.RegularAnalysis.Text
 
     }
 
+    internal enum RegexIRPrefix
+    {
+
+        Prev_Success = 1 << 0,
+        Prev_Fail = 1 << 1,
+        Always = 1 << 2,
+        ExeCondition = Prev_Fail | Prev_Success | Always,
+        Pop_Fail = 1 << 3,
+        Pop_Success = 1 << 4,
+        Pop_Condition = Pop_Success | Pop_Fail,
+
+    }
+
     internal interface IRegexComplex
     {
 
@@ -79,10 +92,7 @@ namespace StgSharp.RegularAnalysis.Text
 
     }
 
-    internal sealed class RegexFindComplexIR(
-                          bool nearest,
-                          int count
-    ) : RegexIR, IRegexComplex
+    internal sealed class RegexFindComplexIR(bool nearest, int count) : RegexIR, IRegexComplex
     {
 
         public bool IsFullyOptimized { get; set; }
@@ -93,9 +103,7 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command => RegexIRCommand.Find_Complex;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t FIND_COMPLEX {(IsNearest ? "NEAREST" : "FURTHEST")} COUNT: {CommandCount}";
         }
@@ -107,16 +115,11 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal abstract RegexIRCommand Command { get; }
 
-        internal abstract string AsCommand(
-                                 int lineNum
-        );
+        internal abstract string AsCommand(int lineNum);
 
     }
 
-    internal sealed class RegexFindSeqIR(
-                          string pattern,
-                          bool isFirst
-    ) : RegexIR
+    internal sealed class RegexFindSeqIR(string pattern, bool isFirst) : RegexIR
     {
 
         public bool IsFirst { get; } = isFirst;
@@ -125,9 +128,7 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command => RegexIRCommand.Find_Seq;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t FIND_SEQ \"{(string.IsNullOrEmpty(Pattern) ? "<EPSILON>" : Pattern)}\"";
         }
@@ -137,46 +138,35 @@ namespace StgSharp.RegularAnalysis.Text
     /// <summary>
     ///   Searches for a certain string pattern or charset from current position.
     /// </summary>
-    internal sealed class RegexMatchSeqIR(
-                          string pattern
-    ) : RegexIR
+    internal sealed class RegexMatchSeqIR(string pattern) : RegexIR
     {
 
         public string Pattern { get; } = pattern;
 
         internal override RegexIRCommand Command => RegexIRCommand.Match_Seq;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t MATCH_SEQ \"{(string.IsNullOrEmpty(Pattern) ? "<EPSILON>" : Pattern)}\"";
         }
 
     }
 
-    internal sealed class RegexMatchSetIR(
-                          string charset
-    ) : RegexIR
+    internal sealed class RegexMatchSetIR(string charset) : RegexIR
     {
 
         public string Charset { get; } = charset;
 
         internal override RegexIRCommand Command => RegexIRCommand.Match_Set;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t MATCH_SET \"{Charset}\"";
         }
 
     }
 
-    internal sealed class RegexConditionIR(
-                          int success,
-                          int fail
-    ) : RegexIR
+    internal sealed class RegexConditionIR(int success, int fail) : RegexIR
     {
 
         public int SuccessCase { get; } = success;
@@ -185,19 +175,14 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command => RegexIRCommand.Condition;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t CONDITION SUCCESS: {SuccessCase} FAIL: {FailCase}";
         }
 
     }
 
-    internal sealed class RegexPackIR(
-                          bool condition,
-                          string name = ""
-    ) : RegexIR
+    internal sealed class RegexPackIR(bool condition, string name = "") : RegexIR
     {
 
         public bool Condition { get; } = condition;
@@ -206,21 +191,14 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command => RegexIRCommand.Pack;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t PACK {(Condition ? "SUCCESS" : "FAIL")} GROUP: \"{GroupName}\"";
         }
 
     }
 
-    internal sealed class RegexCountComplexIR(
-                          int min,
-                          int max,
-                          bool isGreedy,
-                          int operation
-    ) : RegexIR, IRegexCount, IRegexComplex
+    internal sealed class RegexCountComplexIR(int min, int max, bool isGreedy, int operation) : RegexIR, IRegexCount, IRegexComplex
     {
 
         public bool IsGreedy { get; } = isGreedy;
@@ -239,21 +217,14 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command { get; } = RegexIRCommand.Count_Complex;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t COUNT {(IsGreedy ? "GREEDY" : "NON_GREEDY")} MIN: {Min} MAX: {Max} OPERATION: {CommandCount}";
         }
 
     }
 
-    internal sealed class RegexCountSeqIR(
-                          int min,
-                          int max,
-                          bool isGreedy,
-                          string seq
-    ) : RegexIR, IRegexCount
+    internal sealed class RegexCountSeqIR(int min, int max, bool isGreedy, string seq) : RegexIR, IRegexCount
     {
 
         public bool IsGreedy { get; } = isGreedy;
@@ -270,21 +241,14 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command { get; } = RegexIRCommand.Count_Seq;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t COUNT_SEQ {(IsGreedy ? "GREEDY" : "NON_GREEDY")} MIN: {Min} MAX: {Max} SEQ: \"{Sequence}\"";
         }
 
     }
 
-    internal sealed class RegexCountSetIR(
-                          int min,
-                          int max,
-                          bool isGreedy,
-                          string set
-    ) : RegexIR, IRegexCount
+    internal sealed class RegexCountSetIR(int min, int max, bool isGreedy, string set) : RegexIR, IRegexCount
     {
 
         public bool IsGreedy { get; } = isGreedy;
@@ -303,18 +267,14 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command => RegexIRCommand.Count_Set;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t COUNT_SET {(IsGreedy ? "GREEDY" : "NON_GREEDY")} MIN: {Min} MAX: {Max} SET: \"{CharSet}\"";
         }
 
     }
 
-    internal sealed class RegexTryIR(
-                          int count
-    ) : RegexIR, IRegexComplex
+    internal sealed class RegexTryIR(int count) : RegexIR, IRegexComplex
     {
 
         public bool IsFullyOptimized { get; set; }
@@ -323,27 +283,21 @@ namespace StgSharp.RegularAnalysis.Text
 
         internal override RegexIRCommand Command => RegexIRCommand.Try;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t TRY {CommandCount}";
         }
 
     }
 
-    internal sealed class RegexPopIR(
-                          bool isSuccess
-    ) : RegexIR
+    internal sealed class RegexPopIR(bool isSuccess) : RegexIR
     {
 
         public bool IsSuccess { get; } = isSuccess;
 
         internal override RegexIRCommand Command => RegexIRCommand.Pop;
 
-        internal override string AsCommand(
-                                 int lineNum
-        )
+        internal override string AsCommand(int lineNum)
         {
             return $"[{lineNum}]\t POP {(IsSuccess ? "SUCCESS" : "FAIL")}";
         }