In 19—21, use words to describe the language defined by the given regular expression.

21. ( x | y ) y ( x | y ) *

use words to describe the language defined by the given regular expression.

(x|y)y(x|y)*

Given information:

(x|y)y(x|y)*

Concept used:

Write the arbitrary strings for the expression (x|y)y(x|y)*.

Calculation:

It is required to use words to describe the language defined by the given regular expression

(x|y)y(x|y)* .The * in the exponent represents Kleen closure of the expression that is concatenation of the expression with itself any finite number (including zero) of times