In a signal flow graph, _________ is the gain along any path from the input to the output, not passing through any node more than once.

Signal flow graph:

The transfer function from the signal flow graph is given by:

\(H(s) = {C(s) \over R(s)}= {\sum_{k=1}^{\infty}P_kΔ_k \over Δ}\)

P_k = Forward path gain

Δ_k = 1 - (loop gain which does not touch the forward path)

Δ = 1 - (Σloop gain) + (Σnon touching loop gain taken two at a time) - (Σnon touching loop gain taken three at a time)

Forward path gain:

Forward path gain is the gain along any path from the input to the output, not passing through any node more than once.

Feedback path gain:

Feedback path gain is the gain along any path which starts and terminates at the same node, not crossing any other node more than once.