We have the following path.
I tried to create the gain with Mason's formula, which lead me to the following:
Forward Path 1: 1
Loop 1: (1/s)*(2/s)*2
Loop 2: (-1)*(2/s)*2
When I put them together I get:
(1/1 - ((1/s)*(2/s)*2) - ((2/s)*2)) * (-1)*(2/s)*2
If I multiply it with s^2
I get
(-4s)/(s^2+4s+4)
But according to the solution it should be
(s^2 + 4s)/(s^2+4s+4)
So my upper part does not match. Do I use Mason's Gain Formula wrong?