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Exclusive Premises

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
  1. "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.
Critique
Assume that the premises are true. Find an example which allows the premises to be true but which clearly contradicts the conclusion.