"CODE" 34181;
    "COMMENT" MCA 2411;
    "PROCEDURE" REAVECHES(A, N, LAMBDA, EM, V); "VALUE" N, LAMBDA;
    "INTEGER" N; "REAL" LAMBDA; "ARRAY" A, EM, V;
    "BEGIN" "INTEGER" I, I1, J, COUNT, MAX;
        "REAL" M, R, NORM, MACHTOL, TOL;
        "BOOLEAN" "ARRAY" P[1:N];

        NORM:= EM[1]; MACHTOL:= EM[0] * NORM; TOL:= EM[6] * NORM;
        MAX:= EM[8]; A[1,1]:= A[1,1] - LAMBDA;
     GAUSS: "FOR" I:= 1 "STEP" 1 "UNTIL" N - 1 "DO"
        "BEGIN" I1:= I + 1; R:= A[I,I]; M:= A[I1,I];
            "IF" ABS(M) < MACHTOL "THEN" M:= MACHTOL;
            P[I]:= ABS(M) <= ABS(R);
            "IF" P[I] "THEN"
            "BEGIN" A[I1,I]:= M:= M / R;
                "FOR" J:= I1 "STEP" 1 "UNTIL" N "DO"
                A[I1,J]:= ("IF" J > I1 "THEN" A[I1,J]
                "ELSE" A[I1,J] - LAMBDA) - M * A[I,J]
            "END"
            "ELSE"
            "BEGIN" A[I,I]:= M; A[I1,I]:= M:= R / M;
                "FOR" J:= I1 "STEP" 1 "UNTIL" N "DO"
                "BEGIN" R:= ("IF" J > I1 "THEN" A[I1,J] "ELSE"
                    A[I1,J] - LAMBDA);
                    A[I1,J]:= A[I,J] - M * R; A[I,J]:= R
                "END"
            "END"
        "END" GAUSS;
        "IF" ABS(A[N,N]) < MACHTOL "THEN" A[N,N]:= MACHTOL;
        "FOR" J:= 1 "STEP" 1 "UNTIL" N "DO" V[J]:= 1; COUNT:= 0;
     FORWARD: COUNT:= COUNT + 1; "IF" COUNT > MAX "THEN" "GOTO" OUT;
        "FOR" I:= 1 "STEP" 1 "UNTIL" N - 1 "DO"
        "BEGIN" I1:= I + 1;
            "IF" P[I] "THEN" V[I1]:= V[I1] - A[I1,I] * V[I] "ELSE"
            "BEGIN" R:= V[I1]; V[I1]:= V[I] - A[I1,I] * R;
                V[I]:=R
            "END"
        "END" FORWARD;
     BACKWARD: "FOR" I:= N "STEP" -1 "UNTIL" 1 "DO"
        V[I]:= (V[I] - MATVEC(I + 1, N, I, A, V)) / A[I,I];
        R:= 1 / SQRT(VECVEC(1, N, 0, V, V));
        "FOR" J:= 1 "STEP" 1 "UNTIL" N "DO" V[J]:= V[J] * R;
        "IF" R > TOL "THEN" "GOTO" FORWARD;
     OUT: EM[7]:= R; EM[9]:= COUNT
    "END" REAVECHES

        "EOP"