Errors:
A.java:7,2:
  Semantic Error: m1$m2.B in m1.A can not access type m1$m2.B
A.java:7:
  Semantic Error: can not instantiate m1$m2.B no matching constructor found in m1$m2.B
A.java:7,12:
  Semantic Error: m1$m2.B in m1.A can not access type m1$m2.B
A.java:10,2:
  Semantic Error: no visible type named P
A.java:10,12:
  Semantic Error: no visible type named P