Construct a BNF for each of the following languages. Is your grammar ambiguous? If yes, rewrite it to be non-ambiguous. Give an input string of the language and draw the parse tree and AST for your input.

1: The set of valid function calls over { id, num, +, *, (, ), , }. Each call is of the format f(a1, ..., an), where f, a1, ..., an are expressions defined above. Draw a parse tree for the input gcd(x, x + 10).