math-nli: Output if sentence 2 Entails statement 1 or Contradicts statement 1 - 
sentence 1: Sharon had some Pen. Andrew gave him 7 more. Now Sharon has 38 Pen. 
sentence 2:  Sharon had 31 pens in the beginning.
<equate> (38 - 7, 31)
Sharon had some Pen. Andrew gave him 7 more. Now Sharon has 38 Pen. 
 Sharon had 31 pens in the beginning.