Since 1978 when the copyright law was changed, books that are less than fifty years old must not be photocopied without the publisher's permission. thus, any book that has been photocopied since 1978 without the publisher's permission must be at least fifty years old.
the reasoning above exhibits a flaw similar to one in which of the following?
a. any member of the solar system must be either a planet or a moon, so if an asteroid is neither a planet nor a moon, it must not be a member of the solar system.
b. anyone who rides a city bus must buy a bus pass, and since demetrios has a bus pass, he must be riding on a city bus.
c. a driver who turns right must signal, so any driver who did not signal must not have turned right.
d. anyone who legally crosses a national boundary must have a passport; thus anyone who does not have a passport cannot legally cross a national boundary.
e. any wage earner residing in the state must pay state taxes, so since blodwen pays state taxes, she must be resident in the state.