“…We define the set, where denotes the exercise boundary and the payoff function is denoted by q ( S 1 , S 2 ). For any regime α = 1, 2, …, m o , and asset prices S 1 and S 2 , the option values V α ( S 1 , S 2 , t ) in the regime α at time t , satisfies the following free boundary value problems, (see References [26, 28] for details) …”