[sth; sb to do sth; see also: allow, permit, possible
Repeated application of Lemma 2 enables us to write...... [Or: enables one to write; not: “enables to write”]
Also, wherever possible, we work with integer coefficients, enabling us to obtain information about torsion.
In fact, there is a trick which enables one to reduce the time dependent case on Rn to the time independent case on Rn+1.
This enables discontinuous derivations to be built.