Hi,
is it possible to tune maxima to be able to evaluate predicats
constructed as sums of inequalities which boolean value is known?
The following exchange suggests that maxima cannot do this
initially, or I'm missing something essential.
In special case (C8)-(D10) it does fine,
but my attempt to reduce general case to the special one
fails (C11)-(C16).
Thanks for comments
--
Alexander
(C1) declare(a1,real,b1,real,a2,real,b2,real,a3,real,b3,real)$
(C2) assume(b1>a1)$ assume(b2>a2)$
(C3)
(C4) facts();
(D4) [KIND(A1, REAL), KIND(B1, REAL), KIND(A2, REAL), KIND(B2, REAL),
KIND(A3, REAL), KIND(b3, REAL), B1 > A1, B2 > A2]
(C5) is( b1+b2 > a1+a2 );
MACSYMA was unable to evaluate the predicate:
B2 + B1 > A2 + A1
-- an error. Quitting. To debug this try DEBUGMODE(TRUE);)
(C6) assume(a3>0)$ assume(b3>0)$
(C7)
(C8) facts(a3);facts(b3);
(D8) [KIND(A3, REAL), A3 > 0]
(C9)
(D9) [KIND(b3, REAL), b3 > 0]
(C10) is(a3+b3>0);
(D10) TRUE
(C11) declare(dif1,real,dif2,real)$
(C12) dif1::b1-a1$ dif2::b2-a2$
(C13)
(C14) is(dif1>0);
(D14) TRUE
(C15) is(dif2>0);
(D15) TRUE
(C16) is( dif1 + dif2 > 0 );
MACSYMA was unable to evaluate the predicate:
ERREXP1
-- an error. Quitting. To debug this try DEBUGMODE(TRUE);)