I am trying, given ((p ? q) ? r),, to use the Fitch System in order to prove
((p ? q) ? (p ? r)). Any ideas on how I should proceed?
Given ((p ? q) ? r), use the Fitch system to prove ((p ? q) ? (p ? r))

Other Answer1
These steps will help you in this proof :

Relate
 How to fit an ARIMA (p,d,q) model with drift term in R
 In RSA encryption, how do I find d, given p, q, e and c?
 Proving (p>q)>(~q>~p) using Coq Proof Assistant
 Prove that n! is not in O(n^p) for any constant natural number p
 Is (a^p )(b^q) a regular language [closed]
 uppercase 'N' before prolog term: imp(P,Q,Y) : not(P,NP),or(NP,Q,Y)
 R: Lattice QQ Plot with regression Line
 Translating the Q and P function from The Little Schemer into Common Lisp?
 Lowercase letters tail height (g, j, p, q, y)
 Generate X509 certificate or RSA key with known p and q primes
 breaking an n*m image into p*q block in matlab
 RSA decryption knowing n,p,q and cipher only
 RSA crypto  How to choose p, q and e correctly?
 R pch plotting in illustator as “q”
 given a number p , find two elements in array whose product = P