"CODE" 34152;
    "COMMENT" MCA 2312;
    "PROCEDURE" VECSYMTRI(D, B, N, N1, N2, VAL, VEC, EM);
    "VALUE" N, N1, N2;
    "INTEGER" N, N1, N2; "ARRAY" D, B, VAL, VEC, EM;
    "BEGIN" "INTEGER" I, J, K, COUNT, MAXCOUNT, COUNTLIM, ORTH, IND;
        "REAL" BI, BI1, U, W, Y, MI1, LAMBDA, OLDLAMBDA, ORTHEPS,
        VALSPREAD, SPR, RES, MAXRES, OLDRES, NORM, NEWNORM, OLDNORM,
        MACHTOL, VECTOL;
        "ARRAY" M, P, Q, R, X[1:N];
        "BOOLEAN" "ARRAY" INT[1:N];

        NORM:= EM[1]; MACHTOL:= EM[0] * NORM; VALSPREAD:= EM[4] * NORM;
        VECTOL:= EM[6] * NORM; COUNTLIM:= EM[8]; ORTHEPS:= SQRT(EM[0]);
        MAXCOUNT:= IND:= 0; MAXRES:= 0;
        "IF" N1 > 1 "THEN"
        "BEGIN" ORTH:= EM[5]; OLDLAMBDA:= VAL[N1 - ORTH];
            "FOR" K:= N1 - ORTH + 1 "STEP" 1 "UNTIL" N1 - 1  "DO"
            "BEGIN" LAMBDA:= VAL[K]; SPR:= OLDLAMBDA - LAMBDA;
                "IF" SPR < MACHTOL "THEN" LAMBDA:= OLDLAMBDA - MACHTOL;
                OLDLAMBDA:= LAMBDA
            "END"
        "END" "ELSE" ORTH:= 1;
        "FOR" K:= N1 "STEP" 1 "UNTIL" N2 "DO"
        "BEGIN" LAMBDA:= VAL[K]; "IF" K > 1 "THEN"
            "BEGIN" SPR:= OLDLAMBDA - LAMBDA;
                "IF" SPR < VALSPREAD "THEN"
                "BEGIN" "IF" SPR < MACHTOL "THEN"
                    LAMBDA:= OLDLAMBDA - MACHTOL;
                    ORTH:= ORTH +1
                "END" "ELSE" ORTH:= 1
            "END";
            COUNT:= 0; U:= D[1] - LAMBDA; BI:= W:= B[1];
            "IF" ABS(BI) < MACHTOL "THEN" BI:= MACHTOL;
            "FOR" I:= 1 "STEP" 1 "UNTIL" N - 1  "DO"
            "BEGIN" BI1:= B[I + 1];
                "IF" ABS(BI1) < MACHTOL "THEN" BI1:= MACHTOL;
                "IF" ABS(BI) >= ABS(U) "THEN"
                "BEGIN" MI1:= M[I + 1]:= U / BI; P[I]:= BI;
                    Y:= Q[I]:= D[I + 1] - LAMBDA; R[I]:= BI1;
                    U:= W - MI1 * Y; W:= - MI1 * BI1; INT[I]:= "TRUE"
                "END"
                "ELSE"
                "BEGIN" MI1:= M[I + 1]:= BI / U; P[I]:= U; Q[I]:= W;
                    R[I]:= 0; U:= D[I + 1] - LAMBDA - MI1 * W;W:= BI1;
                    INT[I]:= "FALSE"
                "END";
                X[I]:= 1; BI:= BI1
            "END" TRANSFORM
            P[N]:= "IF" ABS(U) < MACHTOL "THEN" MACHTOL "ELSE" U;
            Q[N]:= R[N]:= 0; X[N]:= 1; "GOTO" ENTRY;
        ITERATE: W:= X[1];
            "FOR" I:= 2 "STEP" 1 "UNTIL" N "DO"
            "BEGIN" "IF" INT[I - 1] "THEN"
                "BEGIN" U:= W; W:= X[I - 1]:= X[I] "END"
                "ELSE" U:= X[I]; W:= X[I]:= U - M[I] * W
            "END" ALTERNATE;
        ENTRY: U:= W:= 0;
            "FOR" I:= N "STEP" -1 "UNTIL" 1 "DO"
            "BEGIN" Y:= U; U:= X[I]:= (X[I] - Q[I] * U - R[I] * W) /
                P[I]; W:= Y
            "END" NEXT ITERATION;
            NEWNORM:= SQRT(VECVEC(1, N, 0, X, X)); "IF" ORTH > 1"THEN"
            "BEGIN" OLDNORM:= NEWNORM;
                "FOR" J:= K - ORTH + 1 "STEP" 1 "UNTIL" K - 1 "DO"
                ELMVECCOL(1, N, J, X, VEC, -TAMVEC(1, N, J, VEC, X));
                NEWNORM:= SQRT(VECVEC(1, N, 0, X, X));
                "IF" NEWNORM < ORTHEPS * OLDNORM "THEN"
                "BEGIN" IND:= IND + 1; COUNT:= 1;
                    "FOR" I:= 1 "STEP" 1 "UNTIL" IND - 1,
                    IND + 1 "STEP" 1 "UNTIL" N "DO" X[I]:= 0;
                    X[IND]:= 1; "IF" IND = N "THEN" IND:= 0;
                    "GOTO" ITERATE
                "END" NEW START
            "END" ORTHOGONALISATION;
            RES:= 1 / NEWNORM; "IF" RES > VECTOL "OR" COUNT = 0 "THEN"
            "BEGIN" COUNT:= COUNT + 1; "IF" COUNT <= COUNTLIM "THEN"
                "BEGIN" "FOR" I:= 1 "STEP" 1 "UNTIL" N "DO"
                    X[I]:= X[I] * RES; "GOTO" ITERATE
                "END"
            "END";
            "FOR" I:= 1 "STEP" 1 "UNTIL" N "DO" VEC[I,K]:= X[I] * RES;
            "IF" COUNT > MAXCOUNT "THEN" MAXCOUNT:= COUNT;
            "IF" RES > MAXRES "THEN" MAXRES:= RES; OLDLAMBDA:= LAMBDA
        "END";
        EM[5]:= ORTH; EM[7]:= MAXRES; EM[9]:= MAXCOUNT
    "END" VECSYMTRI

        "EOP"