Intraquery parallelization of HANA queries

Through the great book SAP HANA Administration from Richard Bremer and Lars Breddemann I learned that there are two types of parallelism(Interquery and Intraquery parallelization) . For interquery parallelization it is mentioned that every statement needs his own SQLExecutor thread. I guess this is also valid for a statement which is splited into several parallel processing steps(intraquery).

So my question: Does every parallel processing step of a single query needs his own SQLExecutor thread?

Thanks,

Patrik