Also import `Arith` in numbers to make sure it shadows (just to be sure).

6 jobs for ci/robbert/arith in 11 minutes and 23 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #68593
fp
build-coq.8.10.2

00:04:48

passed #68592
fp-timing
build-coq.8.11.1

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passed #68591
fp
build-coq.8.11.dev

00:11:22

passed #68596
fp
build-coq.8.7.2

00:03:50

passed #68595
fp
build-coq.8.8.2

00:03:47

passed #68594
fp
build-coq.8.9.1

00:04:35