Complex sentence: In this case, one may not reach a contradiction at the end of a branch; rather one brings back information about the value of the branch, when retracing Ariadne's thread, to be used in calculating which move to make.
Split into simpler sentences: In this case, one may not reach a contradiction at the end of a branch. Rather one brings back information about the value of the branch, when retracing Ariadne's thread, to be used in calulating which move to make.