
Exclusive Premises
Definition:
A standard form categorical syllogism has two negative
premises (a negative premise is any premise of the form
'No S are P' or 'Some S is not P').
Examples:
 No Manitobans are Americans, and no
Americans are Canadians, therefore,
no Manitobans are Canadians.
In fact, since Manitoba is a province
of Canada, all Manitobans are Canadians.
Proof:
Assume that the premises are true. Find an example
which allows the premises to be true but which
clearly contradicts the conclusion.
References:
26 May 1995
