This command is just any expression.
Expression is evaluated and result of evaluation is displayed in Results Zone.
Examples:
s=sin(x) ; assigns value sin(x) to variable s
x=pi/2 ; assigns value 1.5707 to variable x
s ; displays in Results Zone: 1
Remark about accuracy. ArtSGraph stores numerical values and performs numerical calculations with approximately 16 decimal digits accuracy. However ArtSGraph displays numbers rounded to 5 decimal digits by default. If you need to see more significant digits, you can increase accuracy using menu Command -> Accuracy.