The phrase "allowed to be either" is correct and usable in written English.
It can be used when discussing options or choices that are permissible within a certain context.
Example: "In this game, players are allowed to be either a knight or a wizard, depending on their preferred play style."
Alternatives: "permitted to be either" or "able to be either".
The pre-stress is allowed to be either tensile or compressive in nature.
The stapes is represented by a moving piston and the bony outer walls are allowed to be either straight or tapered.
B2 is allowed to be either S-polarized (perpendicular to the plane of incidence) or P-polarized (parallel to the plane of incidence).
It should be pointed out that the perturbation term (f t,x)) satisfying some suitable growth conditions, can be allowed to be either a bounded function or an unbounded function, which differs from many existing results in the literature.
The list of preferences is allowed to be either partial or full.
We remark that our results here automatically apply to the binary interference case if we allow to be either zero or one only by comparing the corresponding SINR, that is,, against a predefined threshold, as illustrated in (32) and (33).
Secondly, many find the distinctions invited by the Doctrine of Double Effect and the (five versions of the) Doctrine of Doing and Allowing to be either morally unattractive or conceptually incoherent.
The zone is allowed to be positioned either right-side-up or upside-down with respect to gravity; the zone is subject to various buoyant forces by altering either the zone depth or orientation.
When genes are predicted from genome sequence in step 2, the prediction is allowed to be on either strand and these false-positive predictions therefore do not occur, leading to better results.
Apart from those, other streams are allowed to be allocated to either tubes or shell.
Had Jeff Bridges as Marcus infused even a hint of malice, insensitive jokes would be mean, and had Gil Birmingham as Alberto allowed himself to be either amused or offended, their relationship would seem false.
