Darksteel Ingot. Indestructible is a static ability that means that any permanent that has indestructible cannot be destroyed, and cannot be destroyed as a result of lethal damage.
The less-than symbol (<) represents an inequality in which the number or problem on the left is smaller than that on the right; however, it can be reversed (>) to show that the item on the left is greater than that on the right.
Mathematical and logical symbols also get their meaning from their relation to other symbols. Thus pi is defined as the ratio of the circumference of a circle to its diameter: pi = c/d. So, nonword symbols are much like words but often lack a phonetic form.