TypeScript intersection types properties overlap error

typescript-intersection-types-overlap.ts

interface X {
  c: string;
  d: string;
}

interface Y {
  c: number;
  e: string
}

type XY = X & Y;
type YX = Y & X;

let p: XY;
let q: XY;

p.c = 4; // Error: Type '4' is not assignable to type 'string & number'
q.c = 3; // Error: Type '3' is not assignable to type 'string & number'

p.c = 'text'; // Error: Type 'text' is not assignable to type 'string & number'
q.c = 'text'; // Error: Type 'text' is not assignable to type 'string & number'