H(start,0)
--->E(performed(a1),Ta1).

H(performed(a1),Ta1)
--->E(performed(a2),Ta2)/\Ta2>Ta1
\/E(performed(a3),Ta3)/\Ta3>Ta1.

H(performed(a2),Ta2)
--->EN(performed(a1),Ta1)/\Ta1<Ta2.

H(performed(a3),Ta3)
--->EN(performed(a1),Ta1)/\Ta1<Ta3.

