But it is also used in situations where actually there are several correct solutions and only one of them will be printed. Hence, it would make sense to parametrize this function so that sometimes it says "The correct solution ..." and sometimes "A correct solution ...".
This code: https://github.com/fmidue/output-monad/blob/d469ed0b22df718dde4d4d718a7f6fd54cfe2a0d/output-monad/src/Control/Monad/Output.hs#L160-L166 always says "The correct solution ...".
But it is also used in situations where actually there are several correct solutions and only one of them will be printed. Hence, it would make sense to parametrize this function so that sometimes it says "The correct solution ..." and sometimes "A correct solution ...".