def l=[(1,1,"aaa"),(2,2,"aaa")];
def ll=l.AsQueryable();
_=linq <# from p1,p2,p3 in ll select p1 #>;

Error 5 expected keyword in but found ','

_=linq <# from (p1,p2,p3) in ll select p1 #>;

Error 5 expected identifier but found '('