m1= 2 (bounded)
m2= 8 (unbounded)
12(-8csch[2(x-16t)]^2 - 2sech[x-4t])^2)
u(x,t) = ------------------------------------------
(4coth[2(x-16t)] + 2tanh[x-4t])^2
Time steps: t=-0.5, -0.4, ..., 0, ..., 0.5