diff --git a/test/test.core/ClauseTests.cs b/test/test.core/ClauseTests.cs
new file mode 100644
index 0000000..2c733b8
--- /dev/null
+++ b/test/test.core/ClauseTests.cs
@@ -0,0 +1,58 @@
+using Irony.Interpreter;
+using irules.core;
+
+namespace test.core;
+
+public class ClauseTests : GrammarTester
+{
+    public ClauseTests() : base(new Clause())
+    {
+    }
+
+    [Fact]
+    public void TestA()
+    {
+      Parse("A");
+    }
+    [Fact]
+    public void TestNotA()
+    {
+      Parse("^A");
+    }
+
+    [Fact]
+    public void TestAandB()
+    {
+      Parse("A&B");
+    }
+    [Fact]
+    public void TestAorB()
+    {
+      Parse("A|B");
+    }
+    [Fact]
+    public void TestAorNotB()
+    {
+      Parse("A|^B");
+    }
+    [Fact]
+    public void TestAandNotB()
+    {
+      Parse("A&^B");
+    }
+    [Fact]
+    public void TestNotAandNotB()
+    {
+      Parse("^A&^B");
+    }
+
+
+    [Fact]
+    public void TestSyntactError()
+    {
+       var ex = Assert.Throws<ScriptException>(()=>
+      Parse("B+A"));
+      Assert.Equal(0, ex.Location.Line);
+      Assert.Equal(1, ex.Location.Column);
+    }
+}
\ No newline at end of file
diff --git a/test/test.core/GrammarTester.cs b/test/test.core/GrammarTester.cs
new file mode 100644
index 0000000..531f4a3
--- /dev/null
+++ b/test/test.core/GrammarTester.cs
@@ -0,0 +1,54 @@
+using Irony.Interpreter;
+using Irony.Parsing;
+using Xunit.Sdk;
+
+namespace test.core;
+
+public class GrammarTester
+{
+    private Grammar grammar;
+    private LanguageData language;
+    private Parser parser;
+
+    public GrammarTester(Grammar grammar)
+    {
+         this.grammar = grammar;
+
+         language = new LanguageData(grammar);
+
+         parser = new Parser(language);
+    }
+
+    public Exception LastException { get; private set; }
+    public AppStatus Status { get; private set; }
+    public ParseTree LastScript { get; private set; }
+
+    public object Parse(string script)
+    {
+        try
+        {
+            var parsedScript = parser.Parse(script);
+            if (parsedScript.HasErrors())
+            {
+                Status = AppStatus.SyntaxError;
+                var ex = new ScriptException("Syntax errors found: "
+                + string.Join(", ", parsedScript.ParserMessages.Select(m => $"{m.Message} at line {m.Location.Line}, column {m.Location.Column}" )));
+                ex.Location = parsedScript.ParserMessages.First().Location;
+                throw ex;
+            }
+
+            if (parser.Context.Status == ParserStatus.AcceptedPartial)
+            {
+                throw new Exception("AcceptedPartial");
+            }
+            LastScript = parsedScript;
+            return parsedScript;
+        }
+        catch (Exception ex)
+        {
+            this.LastException = ex;
+            this.Status = AppStatus.Crash;
+            throw;
+        }
+    }
+}
diff --git a/test/test.core/UnitTest1.cs b/test/test.core/UnitTest1.cs
deleted file mode 100644
index 7a55757..0000000
--- a/test/test.core/UnitTest1.cs
+++ /dev/null
@@ -1,49 +0,0 @@
-using Irony.Interpreter;
-using Irony.Parsing;
-using irules.core;
-using Xunit.Sdk;
-
-namespace test.core;
-
-public class UnitTest1
-{
-    public AppStatus Status { get; private set; }
-    public ParseTree LastScript { get; private set; }
-    public Exception LastException { get; private set; }
-
-    [Fact]
-    public void Test1()
-    {
-      Parse("A");
-    }
-
-
-     public object Parse(string script) {
-        
-        var grammar = new Clause();
-        
- var language = new LanguageData(grammar);
-
-      var parser = new Parser(language);
-      try {
-        var parsedScript = parser.Parse(script);
-        if (parsedScript.HasErrors()) {
-           Status = AppStatus.SyntaxError;
-            throw new ScriptException("Syntax errors found: "
-            + string.Join(", ",parsedScript.ParserMessages));
-        }
-
-        if (parser.Context.Status == ParserStatus.AcceptedPartial) {
-          throw new Exception ("AcceptedPartial");
-        }
-        LastScript = parsedScript;
-        return parsedScript;
-      } catch (ScriptException) {
-        throw;
-      } catch (Exception ex) {
-        this.LastException = ex;
-        this.Status = AppStatus.Crash;
-        return null;
-      }
-    }
-}
\ No newline at end of file