c# - How can i get NON contains data from list? -

i have "contains" method need "not contains" method. suggestions?

var resultsofmpd = (from m in engmpdmultiselect                     engmpdmultiitems.select(o => o.eng_mpd_mytechnic_task_no).                     contains(m.eng_mpd_mytechnic_task_no)                     select m); 

is there method that?

var resultsofmpd = (from m in engmpdmultiselect                     engmpdmultiitems.select(o => o.eng_mpd_mytechnic_task_no).                     notcontains(m.eng_mpd_mytechnic_task_no)                     select m); 

use ! operator, this:

var resultsofmpd = m in engmpdmultiselect                    !engmpdmultiitems.select(o => o.eng_mpd_mytechnic_task_no).                    contains(m.eng_mpd_mytechnic_task_no)                    select m; 

by way, don't need select() call.
instead, can write

var resultsofmpd = m in engmpdmultiselect                    !engmpdmultiitems.any(o => o.eng_mpd_mytechnic_task_no == m.eng_mpd_mytechnic_task_no)                    select m; 

or, equivalently,

var resultsofmpd = m in engmpdmultiselect                    engmpdmultiitems.all(o => o.eng_mpd_mytechnic_task_no != m.eng_mpd_mytechnic_task_no)                    select m;