Hello everyone... I'm stuck with a system dynamics project. I keep getting error message in simulink "Result of power is undefined" and I am not sure exactly why i keep getting that error. please note... the error is in a funtion that has a sum and its result has a power. the sum is two functions, one that is given, and the second one is accuired by integrating the given one, multiplying it by factor numeber, and added to it other constants (one of them is dependend on the second integral of the first function). hope i did not confuse anyone. thanks in advance.