signal_wait_time_ms > wait_time_ms for SOS_SCHEDULER_YIELD in sys.dm_os_wait_stats
From the documentation for sys.dm_os_wait_stats (emphasis mine):




Column name
Data type
Description




...
...
...


wait_time_ms
bigint
Total wait time for this wait type in milliseconds. This time is inclusive of signal_wait_time_ms.




If you see signal_wait_time_ms higher than wait_time_ms, then per the current documentation, that is a bug.  You should report it to Microsoft if it's causing you problems so they can investigate where things got off track.  It could be rounding errors in the underlying data that lead to a slight difference (you didn't mention how far off the two values were).
You said this:

the example I am looking at is from the book &quot;Pro SQL Server 2019 wait Statistics&quot; by Van de Laar. In a screenshot on page 120 signal wait is higher for SOS_SCHEDULER_YIELD.

Since the example is from a screenshot in a book, it's quite possible that editorial processes resulted in invalid information making it into the final published result.  In that case, I wouldn't worry about it too much.  You could contact the author to see if it's possible or likely that something happened like that (maybe they were splicing screenshots from multiple tests together for simplicity).