1 free point +


1.1

1p
  0p if doesn't work

1.2

1p
  0p if doesn't work

1.3

1p
  0p if doesn't work

1.4

1p
  0p if doesn't work

1.5

1p
  0p if doesn't work

1.6

1p
  0p if unsound or missing

2.1

1p
  0p if wrong

2.2

2p
  1p right invariant
  + 1p proof
