ela>x=(21,44)  
ela>x  
(21,44)
ela>y=(1,2,"three")  
ela>y  
(1,2,"three")
ela>length y  
3  
ela>y:2  
"three"  
ela>y:0  
1
ela>a=(666,)  
ela>a  
(666,)
ela>(1,2)==(1,2)  
true  
ela>(1,2)==(2,1)  
false
ela>(1,2)++("three", "four")  
(1,2,"three","four")
ela>sum2 (x1, y1) (x2, y2) = (x1+x2, y1+y2)  
ela>sum2 (1,1) (2,2)  
(3,3)
ela>sum_and_diff x y = (x+y, x-y)  
ela>sum_and diff 5,6  
(11, -1)
ela>(x,y)=(5,6)  
ela>x  
5  
ela>y  
6