The description of map:for-each has the following 2 examples:

distinct-values(map:for-each-entry(map{1:"yes", 2:"no"}, function($k, $v){$v})

and 

map:merge(map:for-each(map{"a":1, "b":2}, function($k, $v){map:entry($k, $v+1)})


Both of these should have an extra closing parenthesis ) on the end. Also, the second one is a link to the map:merge definition, which looks a bit strange.