If a person takes the arba minim at Sukkos (Lulav, esrog, hadasim, aravos) and adds on another min in a way they are ovar on bal tosif and they now have 5 minim, are they still yotzee the mitzvah since at the end of it all they still “took” the four minim, even though they added on another one?
This is a matter of dispute among the Rishonim. If one did so, he should take the 4 minim again without a bracha.
Tshuvos Harashba 534, Tur O:C 651 hold one fulfills the mitzvah.
The Rambam, Hilchos Lulav 7:7 holds one does not fulfill the mitzvah.
See Bikurei Yaakov 651:47 that one should take the 4 minim again to ensure fulfillment according to all opinions.