When can an interference proceeding occur between two applications?

An interference proceeding can occur when both applications are in condition for allowance within a specified timeframe. This involves two patent applications that claim the same subject matter, and the patent office must determine which application is the earlier invention. The condition for allowance means that the applications have passed the substantial examination phase and are ready to be granted if no further issues arise. The time limit of 6 months ensures that the interference process occurs while both applications are still actively under consideration, allowing the patent office to resolve the conflict efficiently before the patents are issued.

The other options do not accurately define the requirements for an interference proceeding. For instance, interference is not available for applications solely because they are under the same legal framework (AIA or pre-AIA) or because both have already been granted patents. Additionally, a mix of one application being pre-AIA and the other under AIA does not create a basis for interference, since the legal standards and procedures differ significantly between these two regimes. Therefore, the only correct scenario is when both applications are in condition for allowance, providing a clear path for the interference process to unfold.