What does the jxl Compression setting represent?

[corr]

I have a question about the jxl compression settings. These allow a value between 0-9 for Compression, but I'm wondering which cjxl setting this should be, because the Effort settings don't match in terms of the numbers:

-e EFFORT, --effort=EFFORT
Encoder effort setting. Range: 1 .. 9.
Default: 7. Higher number is more effort (slower).
--brotli_effort=B_EFFORT
Brotli effort setting. Range: 0 .. 11.
Default: 9. Higher number is more effort (slower).