TASK DEFINITION: In this task, you are given a premise, a hypothesis, and an update. The premise sentence describes a real-world situation and is always assumed to be true. The hypothesis sentence describes an assumption or inference that you might make about that situation having read the premise. The update provides additional information about the situation that might weaken or strengthen the hypothesis. A weakener is a statement that weakens the hypothesis, that is, it makes you much less likely to believe the hypothesis is true. A strengthener is a statement that strengthens the hypothesis, that is, it makes you much more likely to believe the hypothesis is true. Your task is to answer with 'strengthener' or 'weakener' if the update strengthens or weakens the hypothesis, respectively.
PROBLEM: Premise: A white-haired older man in a green striped shirt is conducting in the social sciences building.
Hypothesis: A white-haired older man in a green striped shirt and black pants is conducting in the social sciences building.
Update: The man is dressed in semi-formal clothing.

SOLUTION: strengthener

PROBLEM: Premise: Lecture takes place in casual atmosphere.
Hypothesis: The lecture is lengthy.
Update: Most people had packed a lunch.

SOLUTION: strengthener

PROBLEM: Premise: A very skinny Santa Claus greets young children in front of a building.
Hypothesis: A man smiles at children outside while waving
Update: His hands are in his pockets.

SOLUTION:
weakener