How many {after a work by} are to/by {Nathaniel Hawthorne} ?
How much work has Nathaniel Hawthorne produced?
How much work has been done by Nathaniel Hawthorne?
SELECT ( COUNT ( ?m ) AS ?r ) { ?m property:after_a_work_by resource:Nathaniel_Hawthorne }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1877> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q69339 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1877 wd:Q69339 }
4