% aufgabe5.req
% Tutch requirements file

% Task:
% - create a file aufgabe5.tut
% - fill it with proofs of the following propositions
% - run 
%     tutch -r ./aufgabe5 

proof commAnd   : (A & B) => (B & A);
proof deMorgan1 : (A => C) & (B => C) => ((A | B) => C);
annotated proof trans     : (A => B) => (B => C) => (A => C);
annotated proof deMorgan2 : ((A | B) => C) => (A => C) & (B => C);