1. A method of over-approximating an input clock gating function associated with a memory element having a plurality of variables; said method comprising the steps of: selecting one of said plurality of variables to be eliminated from said function; removing said selected variable from said function; calculating, by using a computer, an approximation function to reflect the absence of said selected variable; replacing the original clock gating function with said approximation function; and adjusting the data input of the memory element to accommodate the over-approximation in accordance with a comparison between said input clock gating function and said approximation function.