require 'spec_helper' describe 'Veritas::Logic::Proposition::True#inverse' do subject { true_proposition.inverse } let(:true_proposition) { Logic::Proposition::True.instance } it { should equal(Logic::Proposition::False.instance) } it 'is invertible' do subject.inverse.should equal(true_proposition) end it_should_behave_like 'an idempotent method' end