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.
Okay, how about this: a symbol is a word, an image, or anything that somehow represents a larger idea. In other words, what you see is not just what you get. Symbols are more than meets the eye. They're loaded with meaning.