Perhaps. It’s not clear to me that this is irrelevant to the formal validity of the argument, since “is a typical pig in all respects, and flies” seems to be a contradiction, and replacing a term in an argument with a contradiction isn’t necessarily truth-preserving. But perhaps it is, I don’t know… common sense would reject it, but we’re clearly not operating in the realms of common sense here.
You are right. Perhaps the argument could be modified by replacing “is a flying pig” by “is a typical pig in all respects, and flies”?
Perhaps. It’s not clear to me that this is irrelevant to the formal validity of the argument, since “is a typical pig in all respects, and flies” seems to be a contradiction, and replacing a term in an argument with a contradiction isn’t necessarily truth-preserving. But perhaps it is, I don’t know… common sense would reject it, but we’re clearly not operating in the realms of common sense here.