# Preview onto version 0.3.4

Here you can do some experiments with Rascal. The computation time is
restricted to about 10 secs to prevent high load on server.
Have a look at the documentation or at the examples. If you see wrong plots reload may help.
You job is cancelled as soon someone else accesses this page, so consider a
local installation.
Rascal-toolbox-0.3.4 (C) 2001,2002 Sebastian Ritterbusch
Enter 'help' for help or 'licence' for information about licence and warranty.
"rascal.rc loaded, predefined e, i, pi"
>"The Ratschek-Operator determines if A*X=B is solvable in IR.";
>Precision(1,-8);
>
>Xi(A)=abs(inf(A))<=abs(sup(A))?inf(A)/sup(A):sup(A)/inf(A);
>
>A=[4,8];B=[1,4];C=[-1,2];D=[-3,6];
>
>[Xi(A) Xi(B) Xi(C) Xi(D)]
[0.5 0.25 -0.5 -0.5]
>
>"So there exist unique X from A to B to C and many from C to D and D to C";
>"as Xi(C)=Xi(D)<=0, but none from D or C to B or A, or from B to A."
"as Xi(C)=Xi(D)<=0, but none from D or C to B or A, or from B to A."
>
>[A*[1/4,1/2] B]
[[1,4] [1,4]]
>[B*[-1/4,1/2] C]
[[-1,2] [-1,2]]
>[C*[-3/2,3] D]
[[-3,6] [-3,6]]
>[C*[0,3] D]
[[-3,6] [-3,6]]
>[D/3 C]
[[-1,2] [-1,2]]
>
>"Compare the algebraic results to computed enclosures of B/A and C/B:";
>[B/A [1/4,1/2];C/B [-1/4,1/2]]
[[0.125,1.000] [0.25,0.50];[-1,2] [-0.25,0.50]]
>"The computed intervals enclose the algebraic solutions, but have also";
>"a different interpretation.";
>

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