Description
The permanent of a square matrix
N has the Laplace transform similar to the Laplace transform of the determinant of
N: but all signs are positive. Permanents are used in combinatorics and in probability. They are computationally difficult.
i1 : R = ZZ[a..f];

i2 : M = genericMatrix(R,a,2,3)
o2 =  a c e 
 b d f 
2 3
o2 : Matrix R < R

i3 : permanents(2,M)
o3 = ideal (b*c + a*d, b*e + a*f, d*e + c*f)
o3 : Ideal of R
