Monotonic reasoning is what a knowledge base is of fixed size and can not be updated as in prolog file that is fixed during the clause checking and do not update that automatically but in Non Monotonic reasoning,A Machine got a capability to learn self by getting possible operations on it so when u give some clauses to it ,It does update database if it doesn't create conflicting situations with the database otherwise it would demoted from current set and moved to update set that is not being in use and checked further for its positive clause of fact..

Monotonic loading is a single unvarying load

No.

For example, y = 7 is monotonic. It may be a degenerate case, but that does not disallow it. It is not a bijection unless the domain and range are sets with cardinality 1.

Even a function that is strictly monotonic need not be a bijection. For example, y = sqrt(x) is strictly monotonic [increasing] for all non-negative x. But it is not a bijection from the set of real numbers to the set of real numbers because it is not defined for negative x.

Your preferences are said to be monotonic if more is preferred to less

Nitrogen (N) is monotonic but nitrogen gas (N2) is molecular.