def step_3(w):
    for suffix, rules in suffixes3:
        if w.endswith(suffix):
            for A,B in rules:
                if w.endswith(A): 
                    return R1(w).endswith(A) and w[:-len(A)] + B or w
    return w
Step 3 replaces -ic, -ful, -ness etc. suffixes.
dataset/ETHPy150Open clips/pattern/pattern/vector/stemmer.py/step_3