Minor documentation bug on page https://docs.xtdb.com/xtql/tutorials/introducing-xtql.html. "(Users of existing EDN Datalog databases may already be familiar with https://docs.xtdb.com/xtql/reference/main/xtql/queries.html#_subqueries - in XTQL, because subqueries are a first-class concept, we rely on extensively on these to express a more powerful/composable behaviour.)" should probably be "(Users of existing EDN Datalog databases may already be familiar with https://docs.xtdb.com/xtql/reference/main/xtql/queries.html#_subqueries - in XTQL, because subqueries are a first-class concept, we rely extensively on these to express a more powerful/composable behaviour.)"
Took me a while to spot the difference there! "...rely on extensively on..." should be "...rely extensively on..." So others can see the suggested correction more clearly.