TIME INVARIANCE
Time invariance, in my definition, is such a system that does not stretch or shrink the input function and does not change time shift of input is called "time invariance."
Example of Time invariant system and its proof
$ \,y(t)=e^{x(t)}\, $
Proof:
$ x(t) \to System \to y(t)=e^{x(t)} \to Time Shift(t0) \to z(t)=y(t-t0) $ $ =e^{x(t-t0)} $
