  In this paper, we show that three different generalized similarities enclose
all unitary and anti-unitary symmetries that induce exceptional points in
lower-dimensional non-Hermitian systems. We prove that the generalized
similarity conditions result in a larger class of systems than any class
defined by a unitary or anti-unitary symmetry. Further we highlight that the
similarities enforce spectral symmetry on the Hamiltonian resulting in a
reduction of the codimension of exceptional points. As a consequence we show
that the similarities drive the emergence of exceptional points in lower
dimensions without the more restrictive need for a unitary and/or anti-unitary
symmetry.
