Cats and dogs 1. suppose we are looking at a picture, and someone says "some cat is seen by dog." (that is, some fixed cat has the property that it is seen by every single dog.) assuming this statement, prove that every dog sees some cat. your proof should be semi-formal. for example, at some point, your proof should say "let d be a dog." and the end of your proof should be "therefore, every dog sees some cat." 2. suppose that someone says "every dog sees some cat." does it follow that some cat is is seen by every dog (in the sense above)?