For all a , b and c in R , the equation -LRB- a + b -RRB- · c = -LRB- a · c -RRB- + -LRB- b · c -RRB- holds .

For all a , b and c in R , the equation -LRB- a + b -RRB- + c = a + -LRB- b + c -RRB- holds .
