Diagram of simple filtration: oversize particles in the feed cannot pass through the lattice structure of the filter, while fluid and small particles pass through, becoming filtrate.
An odd function can be identified by replacing both the x and y values with -x and -y values. If the values in your equation are the opposite (positives are negatives and negatives are positives), then the function is odd. Take, for example, this equation y = x^2.
A property of some sets and binary operations, closure means that the output of a binary operation is always within the set of the inputs. Addition is closed for the set of even numbers: 4 + 6 = 10; any two even numbers will add up to an even number.