1 a) Create a regular expression that accepts a single B, then 1 to infinite A's or C's. It must end with a D.

b) Create a regular expression that accepts a Java-style Identifier. Identifiers are used for the names of classes, variables, and more. Make sure to define your sets and use them in your expression.

c) COBOL identifiers must start with a letter and then can be followed by a series of letters, numbers or dashes (minus sign). There is one restriction: dashes cannot appear next to each other. Create a regular expression for COBOL identifiers. Here are some examples: Aliens, First-Name, Tax-Amount, Average-Test-Score