Premise: The choice of a new puck lead to an uncontrolled development of a 'black league' - illegal games, where neither the players, nor the referees or the audience wore protective masks, and where the probability of infection in poorly-ventilated rooms varied between 0.75 and 0.79 to one.

Hypothesis: In the 'black league' nobody present wore a protective mask.
Relation: entailment