registerFunction("-", new SubtractFunction());
registerFunction("*", new MultiplyFunction());
registerFunction("/", new DivideFunction());
registerFunction("%", new ModuloFunction());
registerFunction("?", new ExistsFunction());
registerFunction("!", new NotFunction());
registerFunction("&&", new AndFunction());
registerFunction("||", new OrFunction());
registerFunction("==", new EqualFunction());
registerFunction("#==", new NumericEqualFunction());
registerFunction("!=", new NotEqualFunction());