The phrase "a considerably more difficult" is correct and usable in written English.
It can be used when comparing the difficulty of two or more tasks, situations, or concepts, emphasizing that one is significantly harder than the other.
Example: "The new project is a considerably more difficult challenge than the previous one."
Alternatives: "significantly more challenging" or "much harder".
Cyclic monotonicity however is a considerably more difficult condition to work with than monotonicity.
King is a considerably more difficult and complex subject than he might initially appear.
As a result, multicast design in DTNs is a considerably more difficult problem compared to that in Internet and mobile ad hoc networks.
Determining when a slope will fail is a considerably more difficult challenge, largely due to the difficulty of observing or predicting the processes of material strength degradation.
The mode of transmission for such a disease, the team concluded, would most likely be respiratory, a considerably more difficult route to interrupt than those that are transmitted in blood, for example.
Scientists are now able to make age determinations from much smaller samples and to make them much more rapidly than by radioactive counting, but carbon-14 proved to be a considerably more difficult problem for instrumental development than the other cosmogenic isotopes.
On the first day they drew their face, holding a mirror in one hand and a pencil in the other - a task considerably more difficult than it sounds, but, as both Rhodes and educational examiners are adamant about preparatory work, it is an essential stage.
Choosing a People is considerably more difficult than having a monarch -- or a military man -- chosen for you.
He then needed at least three Republican votes, a task made considerably more difficult by a public promise from the leader of the state Conservative Party to mount primary challenges against any Republican senators who voted for same-sex marriage.
Every year millions of birds migrate to the UK in April and May to breed, many of them from as far away as Africa - a journey made considerably more difficult in the face of the wettest UK spring since records began in 1766 and an unseasonably cold snap.
Spectroscopy, as a measurement, is considerably more difficult than simple photometry, which measures the brightness of astronomical objects through certain filters.
