#print prefix semigroup

#print "======================="

structure [class] has_two_muls (A : Type) extends has_mul A renaming mul→mul1,
                                          private has_mul A renaming mul→mul2

#print prefix has_two_muls

#print "======================="

structure [class] another_two_muls (A : Type) extends has_mul A renaming mul→mul1,
                                                      has_mul A renaming mul→mul2