Task: Text Simplification
Input (English): associativity of addition : for any integers , a , b and c , -lrb- a + b -rrb- + c = a + -lrb- b + c -rrb-.
Output (English): when adding numbers , the sum of -lrb- a + b -rrb- + c is the same as a + -lrb- b + c -rrb-.