I encountered this error When I am translating this sentence:

“All animals, that live at Farm, except possibly some dogs, are either happy or sad.”

Names: farm, Properties: Animal, Dog, Happy, Sad, Relationships: LivesAt

Here is my answer:
all x all z[((Animal(x) & LivesAt(x, farm) & (exists y(-Dog(y) & LivesAt(y, farm)))) -> Animal(z)) <-> (Happy(z) | Sad(z))].

Could someone please check my answer? I do wonder why it is wrong. Thank you so much!