"CODE" 34426;
  "PROCEDURE" DECTRIPIV(SUB, DIAG, SUPER, N, AID, AUX, PIV);
  "VALUE" N; "INTEGER" N; "ARRAY" SUB, DIAG, SUPER, AID, AUX;
  "BOOLEAN" "ARRAY" PIV;
  "BEGIN" "INTEGER" I, I1, N1, N2;
     "REAL" D, R, S, U, T, Q, V, W, NORM, NORM1, NORM2, TOL;
     TOL:= AUX[2]; D:= DIAG[1]; R:= SUPER[1];
     NORM:= NORM2:= ABS(D) + ABS(R); N2:= N - 2;
     "FOR" I:= 1 "STEP" 1 "UNTIL" N2 "DO"
     "BEGIN" I1:= I + 1; S:= SUB[I]; T:= DIAG[I1]; Q:= SUPER[I1];
        NORM1:= NORM2; NORM2:= ABS(S) + ABS(T) + ABS(Q);
        "IF" NORM2 > NORM "THEN" NORM:= NORM2;
        "IF" ABS(D) * NORM2 < ABS(S) * NORM1 "THEN"
        "BEGIN" "IF" ABS(S) <= TOL * NORM2 "THEN"
           "BEGIN" AUX[3]:= I - 1; AUX[5]:= S; "GOTO" EXIT "END";
           DIAG[I]:= S; U:= SUPER[I]:= T / S;
           V:= AID[I]:= Q / S; SUB[I]:= D;
           W:= SUPER[I1]:= -V * D; D:= DIAG[I1]:= R - U * D;
           R:= W; NORM2:= NORM1; PIV[I]:= "TRUE"
        "END" "ELSE"
        "BEGIN" "IF" ABS(D) <= TOL * NORM1 "THEN"
           "BEGIN" AUX[3]:= I - 1; AUX[5]:= D; "GOTO" EXIT "END";
           U:= SUPER[I]:= R / D; D:= DIAG[I1]:= T - U * S;
           AID[I]:= 0; PIV[I]:= "FALSE"; R:= Q
        "END"
     "END";
     N1:= N - 1; S:= SUB[N1]; T:= DIAG[N]; NORM1:= NORM2;
     NORM2:= ABS(S) + ABS(T); "IF" NORM2 > NORM "THEN" NORM:= NORM2;
     "IF" ABS(D) * NORM2 < ABS(S) * NORM1 "THEN"
     "BEGIN" "IF" ABS(S) <= TOL * NORM2 "THEN"
        "BEGIN" AUX[3]:= N2; AUX[5]:= S; "GOTO" EXIT "END";
        DIAG[N1]:= S; U:= SUPER[N1]:= T / S; SUB[N1]:= D;
        D:= DIAG[N]:= R - U * D; NORM2:= NORM1; PIV[N1]:= "TRUE"
     "END" "ELSE"
     "BEGIN" "IF" ABS(D) <= TOL * NORM1 "THEN"
        "BEGIN" AUX[3]:= N2; AUX[5]:= D; "GOTO" EXIT "END";
        U:= SUPER[N1]:= R / D; D:= DIAG[N]:= T - U * S;
        PIV[N1]:= "FALSE"
     "END";
     "IF" ABS(D) <= TOL * NORM2 "THEN"
     "BEGIN" AUX[3]:= N1; AUX[5]:= D; "GOTO" EXIT "END";
     AUX[3]:= N; AUX[5]:= NORM;
 EXIT:
 "END" DECTRIPIV;
        "EOP"