belongsTo doesn't seem to work #4

The example given in the seminar does not work as intended. It gives the following warring/error (I'm not sure since it still prints the final state) :

line 10:10 no viable alternative at input 'forallyin{1..6}if(ybelongsTo'

s1 = { 1 .. 5 }; s2 = { 2, 4, 6, 7 }; a = s1 U s2 ; b = s1 ^ s2; c = s1 \ s2; x = 0; forall y in s2 x = x + y; d = emptySet; forall y in { 1 .. 6 } if (y belongsTo s2) d = d U { y };

The correct way of doing this seems to have changed to using 'in':
if (y in s2) d = d U { y };

The language manual needs to be updated to reflect this change as well as any code examples used in the future.