diff --git a/Configuration/GlobalAssemblyInfo.cs b/Configuration/GlobalAssemblyInfo.cs
index 649bff609..7f7d45f78 100644
--- a/Configuration/GlobalAssemblyInfo.cs
+++ b/Configuration/GlobalAssemblyInfo.cs
@@ -15,7 +15,7 @@ internal static class RevisionClass
 	public const string Major = "3";
 	public const string Minor = "8";
 	public const string Build = "0";
-	public const string Revision = "2944";
+	public const string Revision = "2945";
 
         public const string MainVersion = Major + "." + Minor;
 	public const string FullVersion = Major + "." + Minor + "." + Build + "." + Revision;
diff --git a/Configuration/Version.defs b/Configuration/Version.defs
index 7be07e61c..bff5ecf6b 100644
--- a/Configuration/Version.defs
+++ b/Configuration/Version.defs
@@ -1,4 +1,4 @@
-%COREVERSION%=0
-%REVISION%=2944
 %MINOR%=8
+%REVISION%=2945
+%COREVERSION%=0
 %MAJOR%=3
diff --git a/Release/pabcversion.txt b/Release/pabcversion.txt
index 87b3eae49..46d815b51 100644
--- a/Release/pabcversion.txt
+++ b/Release/pabcversion.txt
@@ -1 +1 @@
-3.8.0.2944
+3.8.0.2945
diff --git a/ReleaseGenerators/PascalABCNET_version.nsh b/ReleaseGenerators/PascalABCNET_version.nsh
index 0bb0b9a52..25530f1f1 100644
--- a/ReleaseGenerators/PascalABCNET_version.nsh
+++ b/ReleaseGenerators/PascalABCNET_version.nsh
@@ -1 +1 @@
-!define VERSION '3.8.0.2944'
+!define VERSION '3.8.0.2945'
diff --git a/TestSuite/CompilationSamples/PABCExtensions.pas b/TestSuite/CompilationSamples/PABCExtensions.pas
index be3cdf9d6..2a6a3b506 100644
--- a/TestSuite/CompilationSamples/PABCExtensions.pas
+++ b/TestSuite/CompilationSamples/PABCExtensions.pas
@@ -121,20 +121,20 @@ end;
 
 ///--
 procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: integer; 
-  step: integer); extensionmethod;
+  step: integer := 1); extensionmethod;
 begin
   SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step);
 end;
 
 ///--
-procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
+{procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
 begin
   SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1);
-end;
+end;}
 
 ///--
 procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex; 
-  step: integer); extensionmethod;
+  step: integer := 1); extensionmethod;
 begin
   if from.IsInverted then
     from.IndexValue := Self.Length - from.IndexValue + 1;
@@ -143,54 +143,48 @@ begin
   SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step);
 end;
 
-///--
-procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
-begin
-  if from.IsInverted then
-    from.IndexValue := Self.Length - from.IndexValue + 1;
-  if &to.IsInverted then
-    &to.IndexValue := Self.Length - &to.IndexValue + 1;
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer; 
-  step: integer); extensionmethod;
-begin
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
-begin
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex; 
-  step: integer); extensionmethod;
-begin
-  if from.IsInverted then
-    from.IndexValue := Self.Length - from.IndexValue + 1;
-  if &to.IsInverted then
-    &to.IndexValue := Self.Length - &to.IndexValue + 1;
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
-begin
-  if from.IsInverted then
-    from.IndexValue := Self.Length - from.IndexValue + 1;
-  if &to.IsInverted then
-    &to.IndexValue := Self.Length - &to.IndexValue + 1;
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
-end;
-
 ///--
 {procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
 begin
-  Self.SystemSliceAssignment(rightValue,situation,from, &to, 1);
+  if from.IsInverted then
+    from.IndexValue := Self.Length - from.IndexValue + 1;
+  if &to.IsInverted then
+    &to.IndexValue := Self.Length - &to.IndexValue + 1;
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1);
+end;}
+
+///--
+procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer; 
+  step: integer := 1); extensionmethod;
+begin
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
+end;
+
+///--
+{procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
+begin
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
+end;}
+
+///--
+procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex; 
+  step: integer := 1); extensionmethod;
+begin
+  if from.IsInverted then
+    from.IndexValue := Self.Length - from.IndexValue;
+  if &to.IsInverted then
+    &to.IndexValue := Self.Length - &to.IndexValue;
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
+end;
+
+///--
+{procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
+begin
+  if from.IsInverted then
+    from.IndexValue := Self.Length - from.IndexValue;
+  if &to.IsInverted then
+    &to.IndexValue := Self.Length - &to.IndexValue;
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
 end;}
 
 //{{{--doc: Конец секции расширений строк для срезов }}} 
diff --git a/TestSuite/CompilationSamples/PABCSystem.pas b/TestSuite/CompilationSamples/PABCSystem.pas
index bc5f18d36..d394ada3b 100644
--- a/TestSuite/CompilationSamples/PABCSystem.pas
+++ b/TestSuite/CompilationSamples/PABCSystem.pas
@@ -13020,10 +13020,10 @@ end;
 function SystemSlice0(Self: string; situation: integer; from, &to: SystemIndex; step: integer := 1): string; extensionmethod;
 begin
   if from.IsInverted then
-    from.IndexValue := Self.Count - from.IndexValue + 1;
+    from.IndexValue := Self.Count - from.IndexValue;
   if &to.IsInverted then
-    &to.IndexValue := Self.Count - &to.IndexValue + 1;
-  Result := SystemSliceStringImpl(Self, situation, from.IndexValue-1, &to.IndexValue-1, step, 0);
+    &to.IndexValue := Self.Count - &to.IndexValue;
+  Result := SystemSliceStringImpl(Self, situation, from.IndexValue, &to.IndexValue, step, 0);
 end;
 
 ///-- 
diff --git a/TestSuite/slice_string_nullbased.pas b/TestSuite/slice_string_nullbased.pas
index 4ea44a239..839ebcc1a 100644
--- a/TestSuite/slice_string_nullbased.pas
+++ b/TestSuite/slice_string_nullbased.pas
@@ -9,6 +9,8 @@ begin
   s := '123456';
   a := s[::2];
   Assert(a='135');
+  a := s[1:^1];
+  Assert(a='2345');
   //s[::2]:=s[1::2];
   //Assert(s='224466');
 end. 
\ No newline at end of file
diff --git a/bin/Lib/PABCExtensions.pas b/bin/Lib/PABCExtensions.pas
index a82f2c8b8..ebc00cdd1 100644
--- a/bin/Lib/PABCExtensions.pas
+++ b/bin/Lib/PABCExtensions.pas
@@ -121,20 +121,20 @@ end;
 
 ///--
 procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: integer; 
-  step: integer); extensionmethod;
+  step: integer := 1); extensionmethod;
 begin
   SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step);
 end;
 
 ///--
-procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
+{procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
 begin
   SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1);
-end;
+end;}
 
 ///--
 procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex; 
-  step: integer); extensionmethod;
+  step: integer := 1); extensionmethod;
 begin
   if from.IsInverted then
     from.IndexValue := Self.Length - from.IndexValue + 1;
@@ -143,54 +143,48 @@ begin
   SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step);
 end;
 
-///--
-procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
-begin
-  if from.IsInverted then
-    from.IndexValue := Self.Length - from.IndexValue + 1;
-  if &to.IsInverted then
-    &to.IndexValue := Self.Length - &to.IndexValue + 1;
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer; 
-  step: integer); extensionmethod;
-begin
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
-begin
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex; 
-  step: integer); extensionmethod;
-begin
-  if from.IsInverted then
-    from.IndexValue := Self.Length - from.IndexValue + 1;
-  if &to.IsInverted then
-    &to.IndexValue := Self.Length - &to.IndexValue + 1;
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
-end;
-
-///--
-procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
-begin
-  if from.IsInverted then
-    from.IndexValue := Self.Length - from.IndexValue + 1;
-  if &to.IsInverted then
-    &to.IndexValue := Self.Length - &to.IndexValue + 1;
-  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
-end;
-
 ///--
 {procedure SystemSliceAssignment(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
 begin
-  Self.SystemSliceAssignment(rightValue,situation,from, &to, 1);
+  if from.IsInverted then
+    from.IndexValue := Self.Length - from.IndexValue + 1;
+  if &to.IsInverted then
+    &to.IndexValue := Self.Length - &to.IndexValue + 1;
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1);
+end;}
+
+///--
+procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer; 
+  step: integer := 1); extensionmethod;
+begin
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
+end;
+
+///--
+{procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: integer); extensionmethod;
+begin
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
+end;}
+
+///--
+procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex; 
+  step: integer := 1); extensionmethod;
+begin
+  if from.IsInverted then
+    from.IndexValue := Self.Length - from.IndexValue;
+  if &to.IsInverted then
+    &to.IndexValue := Self.Length - &to.IndexValue;
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, step, 0);
+end;
+
+///--
+{procedure SystemSliceAssignment0(var Self: string; rightValue: string; situation: integer; from, &to: SystemIndex); extensionmethod;
+begin
+  if from.IsInverted then
+    from.IndexValue := Self.Length - from.IndexValue;
+  if &to.IsInverted then
+    &to.IndexValue := Self.Length - &to.IndexValue;
+  SystemSliceAssignmentStringImpl(Self, rightValue, situation, from, &to, 1, 0);
 end;}
 
 //{{{--doc: Конец секции расширений строк для срезов }}} 
diff --git a/bin/Lib/PABCSystem.pas b/bin/Lib/PABCSystem.pas
index bc5f18d36..d394ada3b 100644
--- a/bin/Lib/PABCSystem.pas
+++ b/bin/Lib/PABCSystem.pas
@@ -13020,10 +13020,10 @@ end;
 function SystemSlice0(Self: string; situation: integer; from, &to: SystemIndex; step: integer := 1): string; extensionmethod;
 begin
   if from.IsInverted then
-    from.IndexValue := Self.Count - from.IndexValue + 1;
+    from.IndexValue := Self.Count - from.IndexValue;
   if &to.IsInverted then
-    &to.IndexValue := Self.Count - &to.IndexValue + 1;
-  Result := SystemSliceStringImpl(Self, situation, from.IndexValue-1, &to.IndexValue-1, step, 0);
+    &to.IndexValue := Self.Count - &to.IndexValue;
+  Result := SystemSliceStringImpl(Self, situation, from.IndexValue, &to.IndexValue, step, 0);
 end;
 
 ///--