Equation or not?

[Arno K]

Better late than never, I thought there must be another way to get that done using the cas:

PHP Code:

EXPORT findeq2()
BEGIN
local j,m;

L0:={"x+y=1","2x+2y<2","3x+3y<=3","4x+4y≤4","5x+5y>5","6x+6y>=6","7x+7y≥7","8x+8y<>8","9x+9y≠9"};
m:=size(L0);
for j from 1 to m do
L0(j):=CAS.expr(L0(j));
//use L9(j):= CAS.expr(L0(j)) to see the results and below here L9(j), too
IF (CAS.part(L0(j),0) == "==") 
THEN return j; 
END;
end;
END; 


Notice, only 1 loop which is exited when the equal sign, transformed to == by the CAS-call, is found. I think that must be faster but cannot reproduce that timing procedure as TEVAL(findeq2()) returns 0.
Here some other "inconsistence" of the cas is found: the last 2 members of the list are transformed to 1 even as the cas does not know anything about x and y and the other inequalities are turned (I dare writing that) from left to right.
Arno