foo.cpp:1:1: error: 'DP' does not name a type
 DP[L1,L2,R1,R2]:=SUM[L2,R1]+A[L1]+A[R2]-MIN{DP[L1,L2+1,R1,R2],DP[L1,L2,R1-1,R2],DP[L2,L2+1,R1,R2],DP[L1,L2,R1-1,R1]}
 ^