I'll keep dissenting: 50/50 is usually not the right solution. Please google founder equity calculator, and use it to start a conversation about who does what and who is committed.
For the YC application, just say that you are not incorporated yet and that you are thinking of splitting 50/50, that should be good enough for them to review.
For the YC application, just say that you are not incorporated yet and that you are thinking of splitting 50/50, that should be good enough for them to review.