25.06.2013 Views

1 transparent par page - Montefiore

1 transparent par page - Montefiore

1 transparent par page - Montefiore

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Démonstration : Par induction structurelle sur T :<br />

◮ Cas de base : Par définition, leaves(leaf) = 1 = 1 + branches(leaf).<br />

◮ Cas récursif : Par définiton,<br />

leaves(branch(T1, T2)) = leaves(T1) + leaves(T2).<br />

Par hypothèse inductive, on a :<br />

leaves(T1) = branches(T1) + 1, leaves(T2) = branches(T2) + 1<br />

et donc<br />

leaves(branch(T1, T2)) = branches(T1) + 1 + branches(T2) + 1.<br />

Par définition,<br />

branches(branch(T1, T2)) = branches(T1) + branches(T2) + 1<br />

et donc :<br />

leaves(branch(T1, T2)) = branches(branch(T1, T2)) + 1.<br />

133

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!