using uCalcSoftware; var uc = new uCalc(); // The transformer 't' belongs to the main 'uc' instance. var t = new uCalc.Transformer(uc); // Define a variable in the transformer's parent context. t.uCalc.DefineVariable("VarX = 123"); // This rule is created within 't' and will need to access VarX. var myRule = t.FromTo("x", "{@Eval: VarX}"); // Get the rule's parent uCalc instance... var parent_uc = myRule.uCalc; // ...and use it to evaluate an expression to prove we have the right context. Console.WriteLine($"Value of VarX in parent context: {parent_uc.Eval("VarX")}"); // Now, run the transformation. The {@Eval} in the rule // correctly finds 'VarX' in its parent uCalc context. Console.WriteLine(t.Transform("The value is: x"));