Dipole formalism with heavy fermions

We extend the dipole formalism of Catani and Seymour to QCD processes invol ving heavy fermions. We give the appropriate subtraction terms together wit h their integrated counterpart. All calculations are done within dimensiona l regularization. Our formulae can be used with three variants of dimension al regularization (conventional dimensional regularization, the 't Hooft-Ve ltman scheme or the four-dimensional scheme).