"CODE" 34420;
      "PROCEDURE" DECSYMTRI(DIAG, CO, N, AUX); "VALUE" N; "INTEGER" N;
      "ARRAY" DIAG, CO, AUX;
      "BEGIN"  "INTEGER" I, N1;
         "REAL" D, R, S, U, TOL, NORM, NORMR;
         TOL:= AUX[2]; D:= DIAG[1]; R:= CO[1];
         NORM:= NORMR:= ABS(D) + ABS(R);
         "IF" ABS(D) <= NORMR * TOL "THEN"
         "BEGIN" AUX[3]:= 0; AUX[5]:= D; "GOTO" EXIT "END";
         U:= CO[1]:= R / D; N1:= N - 1;
         "FOR" I:= 2 "STEP" 1 "UNTIL" N1 "DO"
         "BEGIN" S:= R; R:= CO[I]; D:= DIAG[I];
            NORMR:= ABS(S) + ABS(D) + ABS(R);
            D:= DIAG[I]:= D - U * S;
            "IF" ABS(D) <= NORMR * TOL "THEN"
            "BEGIN" AUX[3]:= I - 1; AUX[5]:= D; "GOTO" EXIT "END";
            U:= CO[I]:= R / D; "IF" NORMR > NORM "THEN" NORM:= NORMR
         "END";
         D:= DIAG[N]; NORMR:= ABS(D) + ABS(R);
         D:= DIAG[N]:= D - U * R;
         "IF" ABS(D) <= NORMR * TOL "THEN"
         "BEGIN" AUX[3]:= N1; AUX[5]:= D; "GOTO" EXIT "END";
         "IF" NORMR > NORM "THEN" NORM:= NORMR;
         AUX[3]:= N; AUX[5]:= NORM;
      EXIT:
      "END" DECSYMTRI;
        "EOP"