I tried to understand to behavior of this circuit when it has no voltage supply at first which means the current state is neither 0 or 1. You can say that there is a 'nothing' input. Then when the switch on digital pulse go to the input but there is a 2-input AND gate but there is only 1 known input because there's no signal at first so I don't know how it would behave this time as the outputs of A, B, and y are neither 0 or 1 so I can't use the truth table or state equation which is a function of the input and present state. There is no present state here to begin with.
If I follow the truth table, then A=0, B=0, x=0 result in A=0, B=1, y=0 in next stage. However, when there is no voltage supply at first. A is not equal 0 because if A equal zero then A'=1 which require voltage supply but there is no voltage supply to make it so