Their problem was that both the membrane current l M and the membrane potential V M are also changing constantly during the action potential. Now if one of these variables could be held constant during the action potential (i.e., V M), measurement of l M would enable them to calculate g M at any instant.
The CMMi Easy button notes on Product Integration (PI) Process Area Product Integration (PI) is one of the core Engineering Process Areas within CMMi, this process is concerned with assembly of product components to build the finished software product.
Product of sequences. The product operator for the product of a sequence is denoted by the capital Greek letter Pi â (in analogy to the use of the capital Sigma â as summation symbol). The product of a sequence consisting of only one number is just that number itself.