“…For example, let T = y 2 • (x + y)/z − sin(x + y) be an expression, and ([6, 7, 4], 3), ( [3,3,6], 2)} be a sample training dataset (here, input feature vector is labeled by [x, y, z]); let expression cache consist of the following key-value entries cache = {(x+y, [3,7,9,13,6]), (y 2 , [4, 16,25,49,9])}. Expression T does not need to be fully evaluated since some of its parts are inside the cache: y 2 and x + y.…”