Path operator "?"

[divral]

Dear QLever team,

I noticed that this operator ("zero or one") does not always work. It is also highlighted in blue (like when it precedes variables) when used as a path modifier.

Query 1 Here, the "?" works. The query outputs the entity that "americium" was named after: "Americas", and also the entity which Americas was named after: "Amerigo Vespucci"

In this larger query, it does not work anymore, outputting only "Americas" for "americium" (number 95): Query 2
It only works when we modify line 13 to use UNION: Query 3

I don't know the exact circumstances of it working or not, but I wanted to make you aware of it. Hopefully, I am not overlooking anything.