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##LIBHDR ACK(M,N) M==0 ? N+1, N==0 ? ACK(M-1,1), ACK(M-1,ACK(M,N-1)) MAIN(;N,M) [ N=0; N<=6 @ [ M=0; M<=3 @ [ WRITEF("ACK(%N,%N) = %N*N",M,N,ACK(M,N)); ++M ]; ++N ] ]