code 34421;
      procedure SOLSYMTRI(DIAG, CO, N, B); value N; integer N;
      array DIAG, CO, B;
      begin integer I;
         real R, S;
         R:= B[1]; B[1]:= R / DIAG[1];
         for I:= 2 step 1 until N do 
         begin R:= B[I] - CO[I-1] * R; B[I]:= R / DIAG[I] end;
         S:= B[N];
         for I:= N - 1 step -1 until 1 do 
         S:= B[I]:= B[I] - CO[I] * S
      end SOLSYMTRI;
        eop