How many co-authors has Mark Steedman had ?
SELECT DISTINCT COUNT ( DISTINCT t1.authorid ) FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid WHERE t1.authorname != "Mark Steedman" AND t2.paperid IN ( SELECT t2.paperid FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid WHERE t1.authorname  =  "Mark Steedman" );
SELECT DISTINCT COUNT ( DISTINCT t1.authorid ) FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid WHERE t1.authorname != "Mark Steedman" AND t2.paperid IN ( SELECT t2.paperid FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid WHERE t1.authorname  =  "Mark Steedman" );
[{'COUNT ( DISTINCT t1.authorid )': 0}]