Question: Romberg approximation procedure in Maple

Hey, I need to write a procedure to calculate the romberg approximation by combining the trapezium rule approximations. The command will be RombInt(f(x),a,b,m,n), where a and b are the 2 limits and m is a number more or equal to 0 which indicates the number of iterations and n is a integer more or equal to m. Also given is that when m=0, this approximation can be called TrapRule(f(x),2^n,a,b). (I have got the procedure for this traprule, if that helps)

So basically this command RombInt should call this TrapRule when m=0, return an error if m>n and return an error if m or n are not non-negative integers. Also when m>0, it should be called by a relation:

R^m_n  = 1/4^m-1(4^mR^m-1_n+1 - R^m-1_n)......The subscript should be underneath the superscript but it doesn't show on here.

Can anyone indicate how I can start with this? Thanks in advance