With no explanation, label text_A→text_B with either "entailment", "neutral" or "contradiction".
text_A: He was a leader in the use of helicopters for medical evacuations of civilians, beginning in 1969, and founded the Society of Thoracic Surgeons.
text_B: He was a leader in the use of helicopters for medical evacuations of civilians, beginning in 1960, and founded the Society of Thoracic Surgeons.
contradiction.