Prove that if [math]A[/math] attracts both [math]B[/math] and [math]C[/math], and [math]A[/math] repels [math]B \cap C[/math], then [math]A[/math] attracts [math]B \cup C[/math]. Is there any example in which [math]A[/math] attracts both [math]B[/math] and [math]C[/math] and repels [math]B \cup C[/math]?