With no explanation, label text_A→text_B with either "entailment", "neutral" or "contradiction".
text_A: An ectopic pacemaker or ectopic focus is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart.
text_B: An ectopic focus is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart.
entailment.