Write a Context-Free grammar in either one of the following way:

1. Use recursion method to define grammar inductively,

2. Use semantic meanning for non-terminals method for the following language: strings have equal numbers of x and y.

For example your language will accept following strings xy, xyxy, xyxyxy, xxxyyy, xxyxyy, but will reject xyx, xxxyy, xxy, yyxxx, ... .

Also show that grammar you created is ambiguos or not by using parse tree approach.