public void Test() { var builder = new SimpleExprBuilder(/*immutable=*/ true); var v0 = builder.False; var v1 = builder.True; var distinct = builder.Distinct(new List <Expr>() { v0, v1 }); using (var writer = new StringWriter()) { var printer = GetPrinter(writer); printer.PrintExpr(distinct); Assert.AreEqual("(distinct false true )", writer.ToString()); } }