Memoryless Property
A system is memoryless iff the system doesn't shift. Which is, the system only depends on the present time and not the past nor the future.
Example:
y[n]= ax(t) memoryless
y[n]= ax(t-t1) non-memoryless
y[n]= t-1+x(t) memoryless
y[n]=t-1+x(t-1) non-memoryless
