Moshe Kurtz asks:
Shalom R Kornfeld.
In the Insights ot the Daf, you cited the Mekor Chayim who concludes that two people who perform the Melachah of Mechamer (which is only a Lav) together are Chayav , even though it is only a Lav and not an Isur Kares.
I heard there would be a nafka minah by Yom Tov also since melacha is a lav and not chatos as shabbos
Moshe Kurtz
The Kollel replies:
This is issue is in dispute among the posskim. See OC 245:3 and 495:3 and Mishnah Berurah ibid. The Gr"a accepts the ruling of the Ma'harshal who maintains that the prohibition applies to Yom tov as well as Shabbos.
Yehuda Landy