From: Rabbi Moshe Sofer
To: Rabbi Chaim
A purely analytical teshuvah responding to five theoretical Torah discussions raised by Rabbi Chaim. The Chasam Sofer critiques several of the arguments as fundamentally flawed, and offers an original resolution distinguishing between bitul of issur beheter (which applies in both dry and wet mixtures) and bitul of heter beheter (which applies only in wet mixtures), based on the laws of basar bechalav and kilayim.
Source: Shu"t Chasam Sofer YD §83