base simple tax query
$tax_query = array( 'relation' => 'AND', array( 'taxonomy' => 'categorieventi', 'terms' => 'altro', 'field' => 'slug', 'operator' => 'IN', 'include_children' => true, ), );
$tax_query = array( 'relation' => 'AND', array( 'taxonomy' => 'categorieventi', 'terms' => 'altro', 'field' => 'slug', 'operator' => 'IN', 'include_children' => true, ), );