The phrase "allow users to define" is correct and usable in written English.
You can use it when discussing features or functionalities in software, applications, or systems that enable users to set parameters or customize settings.
Example: "The new software update will allow users to define their own preferences for notifications and alerts."
Alternatives: "enable users to specify" or "permit users to set".
Hence the need for formal languages that allow users to define periodicities.
What SmartKey did was to allow users to define a single key as representing all the other keystrokes of a given command.
From version 16.5, one can use the Partial Design Feature, which uses test benches to allow users to define those components that are used only for simulations.
The functions set_full_model and set_bkg_full_model allow users to define model expressions that apply instrument responses, or PSFs, to some model components, while not applying the response or the PSF to other model components in the model expression.
Most general-purpose MBS-analysis programs offer a pre- and a post-processor that allow users to define models and evaluate results using the same graphical environment often referred to as a graphical user interface (GUI).
CompChem shall allow users to define and insert new concepts.
NetMatch (Ferro et al., 2007) and NetGrep (Banks et al., 2008) allow user to define queries with specific node features.
UMAT allows users to define the progressive stiffness modification and analyze the fracturing of composite components.
This allows users to define temporal, spatial, and destination constraints which have to hold for single items.
Bioconda improves analysis reproducibility by allowing users to define isolated environments with defined software versions, all of which are easily installed and managed without administrative privileges.
Further advancing the state of the art, eCOMPASS allows users to define arbitrary start/end locations (e.g. the current location of a mobile user) rather than choosing among a fixed set of locations.
