code 41766;
real procedure EXTVALDENS(X, LOC, SCALE);
    value X, LOC, SCALE; real X, LOC, SCALE;
begin
    if SCALE ≤ 0 then
    STATAL3 ERROR(“EXTVALDENS”, 3, SCALE);
    X:= (X - LOC) / SCALE;
    EXTVALDENS:= EXP(-(X + EXP(-X))) / SCALE
end EXTVALDENS;
eop