by more than one also would have no effect on the optimal solution
(
, 
)
or the value of 
.
Similiarly, decreasing
by a small amount has no important effect. In fact,
can be decreased all the way from 1 to -7 before anything happens (no feasible
solutions). Therefore,
is decidedly not a sensitive parameter.
? Let's see what happens
when
is increased by one:
.