Item RangeVariableReference::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    Q_ASSERT_X(context->rangeVariable(slot()), Q_FUNC_INFO, "The range variable must be set.");
    return context->rangeVariable(slot());
}
bool RangeVariableReference::evaluateEBV(const DynamicContext::Ptr &context) const
{
    Q_ASSERT_X(context->rangeVariable(slot()), Q_FUNC_INFO, "The range variable must be set.");
    return Boolean::evaluateEBV(context->rangeVariable(slot()), context);
}