Question of the day

"Ernest Vincent Wright’s Gadsby (1939) follows John Gadsby, a civic-minded man in the declining town of Branton Hills. Concerned about its youth and stagnation, Gadsby organizes the town’s young citizens into a movement for reform and improvement. Through their collective effort, Branton Hills evolves from a neglected, apathetic town into a thriving, modern community. Gadsby becomes mayor, promotes education, public facilities, and civic pride, and helps turn the city into a national model for progress. The novel highlights themes of community service, youth empowerment, moral duty, and optimism, reflecting early 20th-century ideals of social reform and participatory citizenship."

Above is the plot of EVW's book Gadsby. The speciality of Gadsby is the fact that is the longest lipogramic novel, being 50,000 words long (duly advertised).

Here's the character list of Gadsby.

John Gadsby
Nancy Gadsby
Polly Gadsby
Bill Smith
Henry (Hank) Smith
Frank Morgan
Miss Prim
Kurt
Lucy
Mayor Brown
Branton Hills Youth Group
Townsfolk of Branton Hills

Curiously in gadsby, the word "the" itself has not been used due to a certain problem the word "the" poses to his novel's objective, an x lipogram.

The novel, a lipogram, avoids x. To work around common words like "been," or "citizens," Wright employed a wide vocabulary, often using circumlocution to convey his ideas. 

For example, a "wedding" became a "grand church ritual," and "the" might become "this particular".

In describing the population of the town Branton Hills, Wright likely used various descriptions, such as, "townsfolk", "folks""locals""inhabitants""populacing"

Ultimately, the constraint forced him to be creative with his phrasing rather than relying on a simple, single-word substitute for every common word.


What constraint? 

(or)

What x lipogram is being referred to?