1 Know what a set and an element are. 2  Write a mathematical statement with an equal sign or an inequality.  Identify what numbers belong to the set of natural numbers, whole numbers, integers, rational numbers, irrational numbers, and real numbers.
Discogenic spondylosis, which is often thought of as a form of spinal osteoarthritis, refers to a degenerative condition that affects the joints of the spine.
Retrograde spondylolisthesis, or retrolisthesis, is the condition or problem that results when one vertebra (spinal bone) slips backward in relation to the vertebra that is below it. This is a rather rare and unusual problem compared to the more common antegrade spondylolisthsis.ypically and traditionally the term spondylolisthesis by definition means the forward slippage of one vertebra in relation to the one below it, but the additional term antergrade is added to clarify the direction of abnormal movement because of the occasional occurrence of backward movement.