Motion 8 and sqrt

["J. Wolff v. Gudenberg" <wolff@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Nate, Arnold, or anyone else
I try to implement the sqrt function with decorated intervals
then I have to care for the trits defined and unbounded

Given a bare interval X=[x1,x2]
define the decorated interval sqrt(X) as follows

    X          |  sqrt(X)      |deco:defined| deco:unbounded |
-----------------------------------------------------------
x1 =-oo, x2<0 --> empty              -1             1
x1 < x2 < 0   --> empty              -1             -1
x1< 0 < x2    --> [0,sqrt(x2)]        0             -1
x1 <0, x2=oo  --> [0,oo]              0             1
0<=x1 <=x2    --> [sqrt(x1),sqrt(x2)] 1             -1
0<=x1,x2=oo   --> [sqrt(x1), oo]      1             1

Here 1 means sure, 0 don't know, and -1 false
is that correct ?
and how do I propagate given decoration trits, if X is decorated ?
Is there an update operator for trits ?
one unique operator or several different?
user defined?

Juergen
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