If the flag is in exact mode add a previous line with the approximate value
If the flag is approximate, add a new previous line to the output with the exact value
similar as the output shows the numworks
IN: (-(-1)-sqrt(5))/(2*1) [enter]
OUT:
-0.61803398875
(-(sqrt(5))+1)/2
Another option is to place the automatic transcription version, that is, in the input line the original expression is shown, in another line the expression is rewritten in XCAS language