Improve documentation: advanced query "NOT A134C" matches sequences where 134 is N

[fhennig]

Example query:

curl -X 'GET' \
  'https://lapis.pathoplexus.org/ebola-sudan/sample/details?advancedQuery=NOT%20A134C&fields=accession&limit=100&dataFormat=JSON&downloadAsFile=false' \
  -H 'accept: application/json'

response contains "PP_00000PM"

But that sequence has no coverage at position 134: https://pathoplexus.org/ebola-sudan/search?visibility_completeness=true&column_completeness=true&orderBy=completeness&page=1&order=ascending&selectedSeq=PP_00000PM.3

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In my opinion, the query should only match sequences where 134 has coverage. We do not know whether PP_00000PM has a C at 134, it might have.

[fhennig]

I found that what I want, is achieved with "not maybe(A134C)" - this will match all sequences where 134C is either A, T or G (not N)

[fhennig]

I now think maybe the way it is makes sense, but maybe the "not maybe" case could be documented explicitly.

[fengelniederhammer]

Explain this in the LAPIS docs (where advanced queries and "not" on mutations are explained)