program Errors
{
Declarations

	a := 4, b -> Integer;
	d := true, flag   -> boolean;
	array1 := [[1,2],[2,3]], vector -> Array size 4,3;
 	seq1 :=<<1,2,3,4>> -> Sequence;

Statements

	// here we can't make "8/d", because "d" is boolean type
	b = 6 + 8 * 5 - 8/d;

	// "array1" it's a vector bi-dimensional, 
        // so we can't only give one index 
	a = array1[1];

	// we can't give a boolean type to result of
	// indexing array1
	d = array1[0,0];

	// must flag an error because final tail w'll be empty
 	a = head(tail(tail(tail(tail(seq1))))); 
}
