pub fn solve(
  db_state: state.DbState,
  triple: #(ast.Part, String, ast.Part),
  ctx: dict.Dict(String, fact.Value),
  derived: set.Set(fact.Datom),
  as_of_tx: option.Option(Int),
  as_of_valid: option.Option(Int),
) -> List(dict.Dict(String, fact.Value))