solve(ANS,12).
choice([3,14,6,9],ANS),sum(ANS,12)
choice([3,14,6,9],ANS)
ANS=[0,0,0,0]
choice([14,6,9],ANS)
ANS=[0,0,0]
choice([6,9],ANS)
ANS=[0,0]
choice([9],ANS)
ANS=[0]
choice([],ANS)
ANS=[]
0+0+0+0=0
単一化に失敗