inv of singular matrix returns some matrix without error

[gitogito]

I tried this script.

require "numo/linalg"

a = Numo::DFloat[[0, 0],
                 [0, 0]]
p(Numo::Linalg.inv(a))

Result is here.

Numo::DFloat#shape=[2,2]
[[0, 0], 
 [0, 0]]

I think that a matrix with all zero elements has no inverse matrix.