diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index d9b3047..eef50ad 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -23,7 +23,9 @@
       "Bash(Get-ChildItem src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/*.cs)",
       "Bash(Measure-Object)",
       "Bash(Select-Object -ExpandProperty Count)",
-      "PowerShell(dotnet build *)"
+      "PowerShell(dotnet build *)",
+      "Bash(Get-ChildItem src/Strata.SqlTools.Query/*.cs)",
+      "Bash(Select-String -Pattern '^namespace ')"
     ]
   }
 }
diff --git a/src/Strata.SqlTools.Query/CalculationFilterGroup.cs b/src/Strata.SqlTools.Query/CalculationFilterGroup.cs
index b31ef36..29653ee 100644
--- a/src/Strata.SqlTools.Query/CalculationFilterGroup.cs
+++ b/src/Strata.SqlTools.Query/CalculationFilterGroup.cs
@@ -2,24 +2,16 @@ using System.Text.Json.Serialization;
 
 namespace Strata.SqlTools.Query;
 
-public class CalculationFilterGroup
+[method: JsonConstructor]
+public class CalculationFilterGroup(IEnumerable<CalculationFilter> filters, LogicalOperator logicalOperator)
 {
     // Hereditary logical operation applied to all Filters
-    public LogicalOperator LogicalOperator { get; set; }
+    public LogicalOperator LogicalOperator { get; set; } = logicalOperator;
 
-    public IEnumerable<CalculationFilter> Filters { get; set; }
+    public IEnumerable<CalculationFilter> Filters { get; set; } = filters;
 
-    public CalculationFilterGroup()
+    public CalculationFilterGroup() : this([], LogicalOperator.And)
     {
-        LogicalOperator = LogicalOperator.And;
-        Filters = new List<CalculationFilter>();
-    }
-
-    [JsonConstructor]
-    public CalculationFilterGroup(IEnumerable<CalculationFilter> filters, LogicalOperator logicalOperator)
-    {
-        Filters = filters;
-        LogicalOperator = logicalOperator;
     }
 
     public IEnumerable<CalculationFilter> GetValidFilters()
@@ -29,6 +21,6 @@ public class CalculationFilterGroup
 
     public bool IsValid()
     {
-        return Filters != null && Filters.Any(x => x.IsValid());
+        return Filters.All(x => x.IsValid());
     }
 }