math-nli: Output if sentence 2 Entails statement 1 or Contradicts statement 1 - 
sentence 1: Keith had some blackcurrant. Charlie gave him 2 more. Now Keith has 24 blackcurrant. 
sentence 2:  Keith had 17 blackcurrant to begin with.
<equate> (24 - 2, 17)
Keith had some blackcurrant. Charlie gave him 2 more. Now Keith has 24 blackcurrant. 
 Keith had 17 blackcurrant to begin with.