reserve T, X, Y for Subset of MC-wff;
reserve p, q, r, s for Element of MC-wff;

theorem Th36:
  (( p '&' q ) => r ) => ( p => ( q => r )) in IPC-Taut
proof
  set qp = ( q => ( p '&' q ));
  set pr = (( p '&' q ) => r) => ( q => r );
A1: ( p => ( qp => pr )) => ( ( p => qp ) => ( p => pr )) in IPC-Taut by Def14;
A2: p => ( q => ( p '&' q )) in IPC-Taut by Def14;
  p => (( q => ( p '&' q )) => ((( p '&' q ) => r ) => ( q => r ))) in
  IPC-Taut by Th18,Th24;
  then ( ( p => qp ) => ( p => pr )) in IPC-Taut by A1,Def14;
  then
A3: p => ((( p '&' q ) => r ) => ( q => r )) in IPC-Taut by A2,Def14;
  (p => ((( p '&' q ) => r ) => ( q => r ))) => ((( p '&' q ) => r ) => (
  p => ( q => r ))) in IPC-Taut by Th29;
  hence thesis by A3,Def14;
end;
