public void excludeIrrelevant1() {
final String value = "A String, not a Number";
RestrictedDatatype<Number> dr = new RestrictedRealDatatype( dt, IntegerInterval
.allIntegers(), ContinuousRealInterval.allReals(), ContinuousRealInterval
.allReals() );
dr = dr.exclude( singleton( value ) );
assertFalse( dr.contains( value ) );
assertFalse( dr.isEmpty() );
assertFalse( dr.isEnumerable() );
assertFalse( dr.isFinite() );