If by reasonable you mean you want an even distribution of the values 4-9 in x.num[4], then add a dist constraint.
constraint c_dist {num[4] dist {[4:9] :=1};}
If by reasonable you mean you want an even distribution of the values 4-9 in x.num[4], then add a dist constraint.
constraint c_dist {num[4] dist {[4:9] :=1};}