IMHO - and I may of course be wrong - there are (widely) accepted definitions for concurrency and parallelism in the computer science community and in my commen

IMHO - and I may of course be wrong - there are (widely) accepted definitions for concurrency and parallelism in the computer science community and in my comment I tried to present them as good as I could (but the comment is far from being flawless). Assuming I am correct with the previous sentence, there is no way of interpreting concurrency and parallelism this way or another because the terms are fixed by their definition. You can of course look at their relationship from different angels and highlight or ignore different aspects in different situations but this does not change their basic relationship or even definition. I can think of two reasons why one would call a language parallel but no concurrent. First this could obviously happen because somebody is not aware of the meaning of the concepts or uses the words in a non-standard way but I think this is probably not the case - I would be surprised if one designs a concurrent/parallel language and does not know the distinction. My best guess is that the intended meaning of the statement is, that the language is no good for general concurrent task but well suited for SIMD-like concurrent tasks, that is running the some operations on multiple different inputs in parallel. (I have to admit that I know nothing about Sawzall and did not invest any time to figure this out, just guessing.)