"CODE" 34180;
    "COMMENT" MCA 2410;
    "INTEGER" "PROCEDURE" REAVALQRI(A, N, EM, VAL); "VALUE" N;
    "INTEGER" N; "ARRAY" A, EM, VAL;
    "BEGIN" "INTEGER" N1, I, I1, J, Q, MAX, COUNT;
        "REAL" DET, W, SHIFT, KAPPA, NU, MU, R, TOL, DELTA, MACHTOL, S;

        MACHTOL:= EM[0] * EM[1]; TOL:= EM[1] * EM[2]; MAX:= EM[4];
        COUNT:= 0; R:= 0;
     IN: N1:= N - 1;
        "FOR" I:= N, I - 1 "WHILE" ("IF" I >= 1 "THEN"
        ABS(A[I + 1,I]) > TOL "ELSE" "FALSE") "DO" Q:= I;
        "IF" Q > 1 "THEN"
        "BEGIN" "IF" ABS(A[Q,Q - 1]) > R "THEN"
            R:= ABS(A[Q,Q - 1])
        "END";
        "IF" Q = N "THEN"
        "BEGIN" VAL[N]:= A[N,N]; N:= N1 "END"
        "ELSE"
        "BEGIN" DELTA:= A[N,N] - A[N1,N1]; DET:= A[N,N1] * A[N1,N];
            "IF" ABS(DELTA) < MACHTOL "THEN" S:= SQRT(DET) "ELSE"
            "BEGIN" W:= 2 / DELTA; S:= W * W * DET + 1;
                S:= "IF" S <= 0 "THEN" -DELTA * .5 "ELSE"
                W * DET / (SQRT(S) + 1)
            "END";
            "IF" Q = N1 "THEN"
            "BEGIN" VAL[N]:= A[N,N] + S;
                VAL[N1]:= A[N1,N1] - S; N:= N - 2
            "END"
            "ELSE"
            "BEGIN" COUNT:= COUNT + 1;
                "IF" COUNT > MAX "THEN" "GOTO" OUT;
                SHIFT:= A[N,N] + S; "IF" ABS(DELTA) < TOL "THEN"
                "BEGIN" W:= A[N1,N1] - S;
                    "IF" ABS(W) < ABS(SHIFT) "THEN" SHIFT:= W
                "END";
                A[Q,Q]:= A[Q,Q] - SHIFT;
                "FOR" I:= Q "STEP" 1 "UNTIL" N - 1 "DO"
                "BEGIN" I1:= I + 1; A[I1,I1]:= A[I1,I1] - SHIFT;
                    KAPPA:= SQRT(A[I,I] ** 2 + A[I1,I] ** 2);
                    "IF" I > Q "THEN"
                    "BEGIN" A[I,I - 1]:= KAPPA * NU;
                        W:= KAPPA * MU
                    "END"
                    "ELSE" W:= KAPPA; MU:= A[I,I] / KAPPA;
                    NU:= A[I1,I] / KAPPA; A[I,I]:= W;
                    ROTROW(I1, N, I, I1, A, MU, NU);
                    ROTCOL(Q, I, I, I1, A, MU, NU);
                    A[I,I]:= A[I,I] + SHIFT
                "END";
                A[N,N - 1]:= A[N,N] * NU; A[N,N]:= A[N,N] * MU + SHIFT
            "END"
        "END";
        "IF" N > 0 "THEN" "GOTO" IN;
     OUT: EM[3]:= R; EM[5]:= COUNT; REAVALQRI:= N
    "END" REAVALQRI

        "EOP"