Creation annihilation operators - expanding brackets

[yaj]

I would like to normal order the following product of creation-annihilation operators, set up in Maple 16 as follows. The problem is, Maple won't perform "expand" (lowercase e) on the last step below (evaluating sigma3(x) :=[op1+op2]*[op3+op4]*[op5+op6] ); , which makes setting up the entire previous operator groups useless. Appreciate any help.
Thanks
yaj

> with(Physics);
> Setup(mathematicalnotation = true);
print(`output redirected...`); # input placeholder
[mathematicalnotation = true]
> am1 := Annihilation(p, 1, notation = explicit);
print(`output redirected...`); # input placeholder
am1 := a-[p[1]]
> ap1 := Creation(p, 1, notation = explicit);
print(`output redirected...`); # input placeholder
ap1 := a+[p[1]]
> op1 := am1*exp(-i*p[1]*x);
print(`output redirected...`); # input placeholder
op1 := a-[p[1]] exp(-i p[1] x)
> op2 := ap1*exp(i*p[1]*x);
print(`output redirected...`); # input placeholder
op2 := a+[p[1]] exp(i p[1] x)
> am2 := Annihilation(p, 2, notation = explicit);
print(`output redirected...`); # input placeholder
am2 := a-[p[2]]
> ap2 := Creation(p, 2, notation = explicit);
print(`output redirected...`); # input placeholder
ap2 := a+[p[2]]
> op3 := am2*exp(-i*p[2]*x);
print(`output redirected...`); # input placeholder
op3 := a-[p[2]] exp(-i p[2] x)
> op4 := ap2*exp(i*p[2]*x);
print(`output redirected...`); # input placeholder
op4 := a+[p[2]] exp(i p[2] x)
> am3 := Annihilation(p, 3, notation = explicit);
print(`output redirected...`); # input placeholder
am3 := a-[p[3]]
> ap3 := Creation(p, 3, notation = explicit);
print(`output redirected...`); # input placeholder
ap3 := a+[p[3]]
> op5 := am3*exp(-i*p[3]*x);
print(`output redirected...`); # input placeholder
op5 := a-[p[3]] exp(-i p[3] x)
> op6 := ap3*exp(i*p[3]*x);
print(`output redirected...`); # input placeholder
op6 := a+[p[3]] exp(i p[3] x)

> sigma3(x) :=[op1+op2]*[op3+op4]*[op5+op6];
print(`output redirected...`); # input placeholder
sigma3 := Physics:-*(

[a-[p[1]] exp(-i p[1] x) + a+[p[1]] exp(i p[1] x)],

[a-[p[2]] exp(-i p[2] x) + a+[p[2]] exp(i p[2] x)],

[a-[p[3]] exp(-i p[3] x) + a+[p[3]] exp(i p[3] x)])

 

[AndyW]

> expand(sigma3(x));
print(`output redirected...`); # input placeholder
Physics:-*(

[a-[p[1]] exp(-i p[1] x) + a+[p[1]] exp(i p[1] x)],

[a-[p[2]] exp(-i p[2] x) + a+[p[2]] exp(i p[2] x)],

[a-[p[3]] exp(-i p[3] x) + a+[p[3]] exp(i p[3] x)])

In order to perform the "expand" operation on the product of creation-annihilation operators, you will need to use the "expand" command from the Physics package. This command is specifically designed to work with operators and will allow you to expand the product in the desired form. The correct syntax for this command is "expand(expression, operators)". In this case, the expression is "sigma3(x)" and the operators are "a-[p[1]]", "a+[p[1]]", "a-[p[2]]", "a+[p[2]]", "a-[p[3]]", and "a+[p[3]]". Therefore, the correct command to use is "expand(sigma3(x), {a-[p[1]], a+[p[1]], a-[p[2]], a+[p[2]], a-[p[3]], a+[p[3]]})". This should give you the desired expanded form of the product of operators.