Yes, they did answer the question, but–The Devil is in the details.
If a motor oil is labeled “synthetic”, then it is, by definition, 100% synthetic.
However, the question concerned “semi-synthetic” motor oil, and in that case, the exact proportion of synthetic oil to mineral-based oil varies from one brand to another.
If you want an analogy, think about the difference between fruit juices and “fruit drinks”.
The fruit juice is 100% juice, and the “fruit drink” might have anywhere from…perhaps as little as 5% juice… to as much as…maybe…50% juice.
The bottom line is that, if your Owner’s Manual specified synthetic motor oil, you should not be using “semi-synthetic”.