DELETE(C2,5) results in:

Two options to make X = Y safe:

Option 1

If memory location Y contains all the info about Y, then X = Y makes a complete copy of Y; they share nothing; changing one has no effect on the other.

Option 2

If memory location Y contains no info about Y, but just a pointer to the info about Y, then X = Y makes X and Y point to the same place; they share all their info; changing one automatically changes the other.