math-nli: Output if sentence 2 Entails statement 1 or Contradicts statement 1 - 
sentence 1: A waiter had 21 customers in his section. If 12 of them left and the rest of his tables had 3 people at each table, 
sentence 2:  The waiter had -2 tables.
<equate> (((21.0-12.0)/3.0), tables.)
A waiter had 21 customers in his section. If 12 of them left and the rest of his tables had 3 people at each table, 
 The waiter had -2 tables.