I want the code to:

```
deleteCntg([a,a,b,b,b,c,c,c],[a,b,c]).
true.
deleteCntg([a,a,b,b,b,c,c,c],[a,b,b,c].
false.
deleteCntg([a,b,c,a,b,c],[a,b,c]).
false.
deleteCntg([a,b,c,a,b,c],[a,b,c,a,b,c]).
true.
deleteCntg([[a],[b],[b],[a],[a],[b]], [[a],[b],[a],[b]]).
true.
deleteCntg([[a],b,[a,b,[c]],[a,b,[c]],[a,b,[a]],c],X).
X = [[a],b,[a,b,[c]],[a,b,[a]],c] .
```

What is the best way to do this?

Also I have another problem

```
?- subset_add([10,7,3,4,2,1],7,L).
L = [7] ;
L = [3, 4] ;
L = [4, 2, 1] ;
false.
?- subset_add([1,2,3],0,L).
L = [] ;
false.
```

What is the best way to do this?