Basic Block

A basic block (or block for short) is a sequence of instructions such that if any of them is executed, all of them are. That is, there are no branches in except at the beginning and no branches out except at the end.

begin
   i := j;
   if i > k
     then begin k := k + 1; i := i - 1 end
     else i := i + 1;
   writeln(i)
end