namespace System.Dynamic { public abstract class BinaryOperationBinder : DynamicMetaObjectBinder { public ExpressionType Operation { get; } protected BinaryOperationBinder(ExpressionType operation); public DynamicMetaObject FallbackBinaryOperation(DynamicMetaObject target, DynamicMetaObject arg); public abstract DynamicMetaObject FallbackBinaryOperation(DynamicMetaObject target, DynamicMetaObject arg, DynamicMetaObject errorSuggestion); } }