Hp50g emu : graph abs(x)^3 gives negative y-values

[Gil]

As a previous contributors on this forum made me understand,
the graph behavior is consistent with the state flag.

The question is why two DIFFERENT behaviours
when -119 flag is set, I. e. "not rigorous" mode is on for

a) stack/programme calculation
b) drawing graphs.

a) For stack/programme calculation :
absolute value taken into account, indepently of - 119 flag status.

b) And for drawing :
absolute value not taken into account
when - 119 is set.

I don't argue the individual issue of the result,
but I wish somebody could explain to me
the difference of treatment between a) and b).

Regards,
Gil