diff --git a/LINQ/LINQ/Interpreter/Expressions/FuncEval.vb b/LINQ/LINQ/Interpreter/Expressions/FuncEval.vb
new file mode 100644
index 0000000..63078ae
--- /dev/null
+++ b/LINQ/LINQ/Interpreter/Expressions/FuncEval.vb
@@ -0,0 +1,34 @@
+Imports LINQ.Runtime
+
+Namespace Interpreter.Expressions
+
+    Public Class FuncEval : Inherits Expression
+
+        Public Property func As Expression
+        Public Property parameters As Expression()
+
+        Public Overrides Function Exec(env As Environment) As Object
+            Dim invoke As Object = func.Exec(env)
+
+            If invoke Is Nothing Then
+                Throw New NullReferenceException
+            ElseIf TypeOf invoke Is String Then
+                invoke = env.FindInvoke(invoke)
+            ElseIf TypeOf invoke Is SymbolReference Then
+                invoke = env.FindInvoke(DirectCast(invoke, SymbolReference).symbolName)
+            Else
+                Throw New NotImplementedException
+            End If
+
+            Dim args As New List(Of Object)
+
+            For Each item In parameters
+                args.Add(item.Exec(env))
+            Next
+
+            Dim result As Object = invoke(args.ToArray)
+
+            Return result
+        End Function
+    End Class
+End Namespace
\ No newline at end of file
diff --git a/LINQ/LINQ/LINQ.vbproj b/LINQ/LINQ/LINQ.vbproj
index 1ef680f..32889ca 100644
--- a/LINQ/LINQ/LINQ.vbproj
+++ b/LINQ/LINQ/LINQ.vbproj
@@ -158,6 +158,7 @@
     <Compile Include="Interpreter\Executable.vb" />
     <Compile Include="Interpreter\Expressions\BinaryExpression.vb" />
     <Compile Include="Interpreter\Expressions\ArrayExpression.vb" />
+    <Compile Include="Interpreter\Expressions\FuncEval.vb" />
     <Compile Include="Interpreter\Expressions\Keywords\Options\TakeItems.vb" />
     <Compile Include="Interpreter\Expressions\Keywords\Options\PipelineKeyword.vb" />
     <Compile Include="Interpreter\Expressions\MemberReference.vb" />
@@ -196,6 +197,9 @@
       <DependentUpon>Settings.settings</DependentUpon>
       <DesignTimeSharedInput>True</DesignTimeSharedInput>
     </Compile>
+    <Compile Include="Runtime\Callable.vb" />
+    <Compile Include="Runtime\InternalInvoke.vb" />
+    <Compile Include="Runtime\Math.vb" />
     <Compile Include="Runtime\DataFrameExtensions.vb" />
     <Compile Include="Runtime\DataSourceDriver.vb" />
     <Compile Include="Runtime\Registry.vb" />
diff --git a/LINQ/LINQ/Runtime/Callable.vb b/LINQ/LINQ/Runtime/Callable.vb
new file mode 100644
index 0000000..b1ee5ff
--- /dev/null
+++ b/LINQ/LINQ/Runtime/Callable.vb
@@ -0,0 +1,31 @@
+Imports System.Reflection
+
+Namespace Runtime
+
+    Public Class Callable
+
+        Dim method As MethodInfo
+
+        Public ReadOnly Property name As String
+            Get
+                Return method.Name
+            End Get
+        End Property
+
+        Sub New(method As MethodInfo)
+            Me.method = method
+        End Sub
+
+        Sub New(math1 As Func(Of Double, Double))
+            Call Me.New(math1.Method)
+        End Sub
+
+        Sub New(math2 As Func(Of Double, Double, Double))
+            Call Me.New(math2.Method)
+        End Sub
+
+        Public Function Evaluate(params As Object()) As Object
+
+        End Function
+    End Class
+End Namespace
\ No newline at end of file
diff --git a/LINQ/LINQ/Runtime/Environment.vb b/LINQ/LINQ/Runtime/Environment.vb
index 64c5abe..52e7f35 100644
--- a/LINQ/LINQ/Runtime/Environment.vb
+++ b/LINQ/LINQ/Runtime/Environment.vb
@@ -27,6 +27,10 @@ Namespace Runtime
             Me.parent = parent
         End Sub
 
+        Public Function FindInvoke(name As String) As Callable
+            Return InternalInvoke.FindInvoke(name)
+        End Function
+
         Public Function HasSymbol(name As String) As Boolean
             If symbols.ContainsKey(name) Then
                 Return True
diff --git a/LINQ/LINQ/Runtime/InternalInvoke.vb b/LINQ/LINQ/Runtime/InternalInvoke.vb
new file mode 100644
index 0000000..05cb077
--- /dev/null
+++ b/LINQ/LINQ/Runtime/InternalInvoke.vb
@@ -0,0 +1,30 @@
+Imports System.Reflection
+
+Namespace Runtime
+
+    Public Class InternalInvoke
+
+        Shared ReadOnly invokes As Dictionary(Of String, Callable)
+
+        Shared Sub New()
+            Call loadInternal(Of Math)()
+        End Sub
+
+        Private Shared Sub loadInternal(Of T As Class)()
+            Dim type As TypeInfo = GetType(T)
+            Dim fields As FieldInfo() = type.DeclaredFields _
+                .Where(Function(m)
+                           Return m.IsStatic AndAlso m.FieldType Is GetType(Callable)
+                       End Function) _
+                .ToArray
+
+            For Each item As FieldInfo In fields
+                invokes(item.Name) = item.GetValue(Nothing)
+            Next
+        End Sub
+
+        Public Shared Function FindInvoke(name As String) As Callable
+            Return invokes.TryGetValue(name)
+        End Function
+    End Class
+End Namespace
\ No newline at end of file
diff --git a/LINQ/LINQ/Runtime/Math.vb b/LINQ/LINQ/Runtime/Math.vb
new file mode 100644
index 0000000..92d1b32
--- /dev/null
+++ b/LINQ/LINQ/Runtime/Math.vb
@@ -0,0 +1,12 @@
+Imports stdnum = System.Math
+
+Namespace Runtime
+
+    Friend Class Math
+
+        Public Shared ReadOnly abs As New Callable(AddressOf stdnum.Abs)
+        Public Shared ReadOnly min As New Callable(AddressOf stdnum.Min)
+        Public Shared ReadOnly max As New Callable(AddressOf stdnum.Max)
+
+    End Class
+End Namespace
\ No newline at end of file
diff --git a/LINQ/test/query.linq b/LINQ/test/query.linq
index ffaf472..054f084 100644
--- a/LINQ/test/query.linq
+++ b/LINQ/test/query.linq
@@ -9,5 +9,5 @@ SELECT x.LipidIon,
 	   x.Formula,
 	   x.PeakQuality,
 	   x."m-Score"
-ORDER BY lipidName
+ORDER BY pow("m-Score", PeakQuality)
 TAKE 15
\ No newline at end of file