diff --git a/ComputerAlgebra/LinqCompiler/CompileExpression.cs b/ComputerAlgebra/LinqCompiler/CompileExpression.cs
index 520c0a2..1b73508 100644
--- a/ComputerAlgebra/LinqCompiler/CompileExpression.cs
+++ b/ComputerAlgebra/LinqCompiler/CompileExpression.cs
@@ -110,6 +110,35 @@ protected override LinqExpr VisitPower(Power P)
 
         protected override LinqExpr VisitCall(Call C)
         {
+            if (C.Target.Name == "Ln")
+            {
+                var arg = C.Arguments.Single();
+                if (arg is Sum sum)
+                {
+                    if (sum.Terms.Count() == 2)
+                    {
+                        var terms = sum.Terms.ToArray();
+                        var a = terms[0];
+                        var b = terms[1];
+
+                        var (match, lnArgs) = (a, b) switch
+                        {
+                            (Constant c, Call f) when c.Value == 1 && f.Target.Name == "Exp" => (true, f.Arguments),
+                            (Call f, Constant c) when c.Value == 1 && f.Target.Name == "Exp" => (true, f.Arguments),
+                            _ => (false, null),
+                        };
+
+                        if (match)
+                        {
+                            var compiledArgs = lnArgs.Select(i => Visit(i)).ToArray();
+                            return Int(C, LinqExpr.Call(
+                                target.Module.GetFunction("Ln1Exp", compiledArgs.Select(i => i.Type).ToArray()),
+                                compiledArgs));
+                        }
+                    }
+                }
+
+            }
             LinqExpr[] args = C.Arguments.Select(i => Visit(i)).ToArray();
             return Int(C, LinqExpr.Call(
                 target.Module.Compile(C.Target, args.Select(i => i.Type).ToArray()),
diff --git a/ComputerAlgebra/LinqCompiler/StandardMath.cs b/ComputerAlgebra/LinqCompiler/StandardMath.cs
index 4395f1a..f56db47 100644
--- a/ComputerAlgebra/LinqCompiler/StandardMath.cs
+++ b/ComputerAlgebra/LinqCompiler/StandardMath.cs
@@ -7,6 +7,13 @@ namespace ComputerAlgebra.LinqCompiler
     /// </summary>
     public class StandardMath
     {
+        private static double ExpKnee = 50;
+        static StandardMath()
+        {
+            _knee = Math.Exp(ExpKnee);
+            _b = _knee - _knee * ExpKnee;
+        }
+        public static double Ln1Exp(double x) => x > 50d ? x : Math.Log(1d + Math.Exp(x));
         public static double Abs(double x) { return x < 0 ? -x : x; }
         public static double Sign(double x) { return x > 0 ? 1 : (x < 0 ? -1 : 0); }
 
@@ -42,7 +49,11 @@ public class StandardMath
         public static double ArcCoth(double x) { return ArcTanh(1 / x); }
 
         public static double Sqrt(double x) { return Math.Sqrt(x); }
-        public static double Exp(double x) { return Math.Exp(x); }
+
+        private static double _knee;
+        private static double _b;
+
+        public static double Exp(double x) => x > ExpKnee ? _knee * x + _b : Math.Exp(x);
         public static double Ln(double x) { return Math.Log(x); }
         public static double Log(double x, double b) { return Math.Log(x, b); }
         public static double Pow(double x, double y) { return Math.Pow(x, y); }