  Heisenberg uncertainty relation is at the origin of understanding minimum
uncertainty states and squeezed states of light. In the recent past, sum
uncertainty relation was formulated by Maccone and Pati [Phys. Rev. Lett. 113,
260401 (2014)] which is claimed to be stronger than the existing
Heisenberg-Robertson product uncertainty relation for the set of two
incompatible observables. We deduce a different sum uncertainty relation that
is weaker than the previous but necessary and sufficient to define MUS for sum
uncertainty relations. We claim that the MUS for the sum uncertainty relation
is always the MUS for the traditional product uncertainty relation. This means
that the definition of squeezed states remains completely unaffected by the
stronger sum uncertainty relation.
