We now indicate how that difficulty can be circumvented.
To get around $\langle$overcome$\rangle$ this difficulty, assume ......
The proof of Theorem 6 bypasses this difficulty.
We now indicate some of the inherent difficulties.
But this obvious attack runs into a serious difficulty.
The analogue of Theorem 1 presents no difficulty.
The difficulty disappears entirely if we think of our functions as elements of $E$.
The only difficulty is in showing that ......
As $M$ is ordered, we have no difficulty in assigning a meaning to $(a,b)$. [Not: “difficulty to assign”]
The difficulty is that it is by no means clear what one should mean by a normal family.
The difficulty consists in generalizing (b).
Some such difficulty is to be expected.
The assumption that the test statistics are identically distributed can be relaxed without much difficulty.