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.
And the symbol for doing that is the greater than symbol. This literally would be read as 3 is greater than 1. 3 is a larger quantity. And if you have trouble remembering what this means-- greater than-- the larger quantity is on the opening. I guess if you could view this as some type of an arrow, or some type of symbol, but this is the bigger side.