"CODE" 35061;
"REAL" "PROCEDURE" GAMMA(X); "VALUE" X; "REAL" X;
"BEGIN" "REAL" Y, S, F, G, ODD, EVEN;
    "BOOLEAN" INV;
    "IF" X < .5 "THEN"
    "BEGIN" Y:= X - ENTIER(X / 2) * 2; S:= 3.14159 26535 8979;
        "IF" Y >= 1 "THEN" "BEGIN" S:= - S; Y:= 2 - Y "END";
        "IF" Y >= .5 "THEN" Y:= 1 - Y; INV:= "TRUE"; X:= 1 - X;
        F:= S / SIN(3.14159 26535 8979 * Y)
    "END"
    "ELSE" INV:= "FALSE";
    "IF" X > 22 "THEN" G:= EXP(LOG GAMMA(X)) "ELSE"
    "BEGIN" S:= 1;
    NEXT: "IF" X > 1.5 "THEN"
        "BEGIN" X:= X - 1; S:= S * X; "GOTO" NEXT "END";
        G:= S / RECIP GAMMA(1 - X, ODD, EVEN)
    "END";
    GAMMA:= "IF" INV "THEN" F / G "ELSE" G
"END" GAMMA

        "EOP"