wxMaxima version: 13.4.0

Maxima version: 5.31.1

Maxima build date: 2013-09-24 09:49:12

Host type: i686-pc-mingw32

Lisp implementation type: GNU Common Lisp (GCL)

Lisp implementation version: GCL 2.6.8

(im:2,assume(u>0),assume(a>0), lisv:makelist([x[1,j],x[2,j]],j,1,3)
,tt:product( exp(-a*(x[1,j]^2+x[2,j]^2) -u^2*(x[1,j]-x[2,j])^2),j,1,3)
,for i1j1:0 thru im do for i2j1:i1j1 thru im step 2 do for i1j2:i1j1 thru im
do for i2j2:i1j2 thru im step 2 do for i1j3:i1j2+1-signum(2-(-1)^i1j1-
(-1)^i1j2) thru im step 2-signum(2-(-1)^i1j1-(-1)^i1j2) do for i2j3:i1j3
thru im step 2 do(t:ttx[1,1]^i1j1x[2,1]^i2j1x[1,2]^i1j2x[2,2]^i2j2x[1,3]
^i1j3x[2,3]^i2j3,for i thru 2 do for j thru 3 do t:integrate(t,lisv[j][i],-inf,inf)
/*,t:factor(t) */
,disp(t), t:integrate(t,u,0,inf)
,ldisp([i1j1,i2j1,i1j2,i2j2,i1j3,i2j3,factor(t)])) );

Note the `/*,t:factor(t) */`

is commented out. If we uncomment this then all is

well whether we do or do not precede this above routine with algebraic:true.

Now beginning about the 3rd or 4th output stage with the [0,0,0,1,1,1,1,...

signature with default algebraic:false then it only gives the integral in

noun form without evaluation. If we precede the whole routine with

algebraic:true it err's out. Note this has nothing to do with the use of signum(...)'s.

Again if we uncomment and use t:factor(t) where written above

then all is well.

The point is maxima should evaluate the integral without one having to

explicitly put in the t:factor(t) and besides this there is a bug in

algebraic:true as appears when we don't use the t:factor(t).