Dear Mehmet,
I feel I should have explained more

For example consider following:
out = (a- dError/dOut * Error)* Error

if Error increases and Out increases it redeces gain
if Error decreases and Out increases it increases gain
if Error increases and Out decreases it increases gain
if Error decreases and Out decreases it redeces gain

this system dosn't go toward unstability in my opinion but unfortunately I have no suitable software for simulation.




thank you very much.