// ----------- Numbers
@Override
protected ValueHolder evaluateBoolean(final FormulaContext ctx, final ValueHolder[] params) {
Collection<boolean[]> values = new ParameterCollectionBoolean(params, isPermutative);
ValueHolder ret = ValueHolder.createValueHolder(boolean.class, values.size());
for (boolean[] value : values) {
ret.add(computer.compute(value[0], value[1]));
}