ffi - true - false response of query from prolog in C# -

i using swi- prolog c# front end. want to display whether the query executed or not in mmessagebox. need answer in 'true' or 'false' comes in prolog console. here code:

static void main(string[] args) {      environment.setenvironmentvariable("swi_home_dir", @"c:\program files\swipl");     environment.setenvironmentvariable("path", @"c:\program files\swipl");     environment.setenvironmentvariable("path", @"c:\program files\swipl\bin");     string p1 = @"c:\program files\swipl\try9.pl";      string[] p = { "-q", "-f", p1 };     plengine.initialize(p);     try     {          plquery q = new plquery("get(sam,age(26)).");          // here need responce of prolog engine of above query whether true or false .         console.readline();      }     catch (plexception ex)     {         console.writeline("exception handeled" + ex.message);     }  } 

let me state first of have never used swi-prolog, may not you're looking for. able read documentation , samples... :)

i found page: http://www.lesta.de/prolog/swiplcs/generated/html/m_sbssw_swiplcs_plquery__ctor.htm

and sounds might want following. or @ least maybe helps started?

try {     using (var q = new plquery("get(sam,age(26))."))     {         if (q.solutions == null) // not sure if possible?         {             console.writeline("query did not run successfully.");         }         else         {             console.writeline("query returned {0} items.", q.solutions.count());         }                    } } catch (plexception ex) {     console.writeline("exception handled: " + ex.message); }  console.readline();