In a closed economy IS-PC-MR model. With 1 period lag in the effect of real interest rates and adaptive expectations for inflation. Suppose that in period t (and in advance of interest rates being set for period t) the central bank announces that the inflation target is to be reduced from 2% to 1% with immediate effect.

How to graph the adjustment of r, y, pi from t until new inflation target is achieved?

And what will the effects on involuntary unemployment and voluntary unemployment be in this case? (How to graph the relationship between PC and WS-PS?)