/x\ tanh|-| \2/
2/x\ tanh |-| 1 \2/ - - -------- 2 2
/ 2/x\\ /x\ |-1 + tanh |-||*tanh|-| \ \2// \2/ ----------------------- 2
/ 2/x\\ / 2/x\\ -|-1 + tanh |-||*|-1 + 3*tanh |-|| \ \2// \ \2// ----------------------------------- 4