PLEASE PLEASE an Undo

[compsystems]

there is a problem, [SHIFT]+[PASTE] it is not 100% functional =[

example

x / y [ENTER]
ans + 5 [ENTER] (x / y)+5
ans / z [ENTER] ((x / y)+5)/z
ans * 3 [ENTER] (x/y+5)/z*3

by rerunning the entries [SHIFT]+[PASTE], you lose ANS pointer,


One possible solution is that ANS should be evaluated in history as does calculators ti68K or here is also a ENTRY (#) command to call the input line