"CODE" 35191;
  "PROCEDURE"  BESS KA01(A, X, KA, KA1); "VALUE" A, X;
  "REAL" A, X, KA, KA1;
  "IF" A = 0 "THEN"
  "BEGIN"
    BESS K01(X,KA,KA1)
  "END" "ELSE"
  "BEGIN" "REAL" F, G, H, PI; "INTEGER" N, NA; "BOOLEAN" REC, REV;
    PI:= 4 * ARCTAN(1);
    REV:= A < -.5; "IF" REV "THEN" A:= -A-1;
    REC:= A >=  .5; "IF" REC "THEN"
    "BEGIN" NA:=ENTIER(A+.5); A:= A - NA "END";
    "IF" A = .5 "THEN" F:= G:= SQRT(PI / X / 2) * EXP (-X) "ELSE"
    "IF" X < 1 "THEN"
    "REAL" A1, B, C, D, E, P, Q, S;
      B:=X/2;D:=-LN(B);E:=A*D;C:=A*PI;
      C:="IF" ABS(C)<"-15 "THEN" 1 "ELSE" C/SIN(C);
      S:="IF" ABS(E)<"-15 "THEN" 1 "ELSE" SINH(E)/E;
      E:=EXP(E);A1:=(E+1/E)/2;G:=RECIP GAMMA(A,P,Q)*E;
      KA:=F:=C*(P*A1+Q*S*D);E:=A*A;
      P:=.5*G*C;Q:=.5/G;C:=1;D:=B*B;KA1:=P;
      "FOR" N:=1,N+1 "WHILE" H/KA+ABS(G)/KA1>"-15 "DO"
      "BEGIN" F:=(F*N+P+Q)/(N*N-E);C:=C*D/N;
        P:=P/(N-A);Q:=Q/(N+A);G:=C*(P-N*F);
        H:=C*F;KA:=KA+H;KA1:=KA1+G
      "END";
      F:=KA;G:=KA1/B
    "END" "ELSE"
    "BEGIN" "REAL" EXPON;
      EXPON:= EXP(-X); NONEXP BESS KA01(A, X, KA, KA1);
      F:= EXPON * KA; G:= EXPON * KA1
    "END";
    "IF" REC "THEN"
    "BEGIN" X:= 2 / X;
      "FOR" N:= 1 "STEP" 1 "UNTIL" NA "DO"
      "BEGIN" H:= F + (A + N) * X * G; F:= G; G:= H "END"
    "END";
    "IF" REV "THEN" "BEGIN" KA1:= F; KA:= G "END" "ELSE"
    "BEGIN" KA:= F; KA1:= G "END"
  "END" BESS KA01;
        "EOP"