Let **F** be a differential field with constant field **K**. For
suppose that the equation (i.e. ) has a solution
where **G** is an elementary extension of **F** having the same
constant field **K**. Then there exist
(note, they are in the same field as **f**, the integrand) and there also
exist constants in **K** (a little sleight-of-hand
with the constants, there---necessary extensions have been made to
create the field **G** already) such that

or, in other words,

That is, * All You Need is Logs* (John Lennon nearly had it right).

Thu Nov 23 10:59:42 PST 1995