I've got these arithmetic expressions a  ::=  n  |  x  |  a1 + a2  |  a1 ? a2  |  a1  a2  which are a part of language.An undefined element is allowed  which extends the set of intergers to Z{}.Problem:I need to define the function A: Aexp  (State  Z{})by defining equations for each form of the arithmetic expression a.Now I've tried to come up with an solution but I am pretty sure I am wrong and I gotta admit I am pretty stuck.Some help understanding this problem would be great.
Defining function for arithmetic expressions
semantics;denotational semantics