  In [5] Soare and Stob prove that if $A$ is an r.e. set which isn't computable
then there is a set of the form $A \oplus W^A_e$ which isn't of r.e. Turing
degree. If we define a properly $n+1$-REA set to be an $n+1$-REA set which
isn't Turing equivalent to any $n$-REA set this result shows that every
properly 1-REA set can be extended to a properly 2-REA set. This result was
extended in [1] by Cholak and Hinman who proved that every 2-REA set can be
extended to a properly 3-REA set. This leads naturally to the hypothesis that
every properly $n$-REA set can be extended to a properly $n+1$-REA set. In this
paper, we show this hypothesis is false and that there is a properly $3$-REA
set which can't be extended to a properly $4$-REA set.
