How to write a successful loop without really trying.

RULE ONE:
	A loop must contain at least one "exit" statement.


	loop
		.
		exit when done
		.
	end loop


RULE TWO:
	The variables in the exit statement must have a value.

	var done: boolean := false
	var s: string 
	
	loop
		exit when done
		get s
		done := s="quit"
		put s
	end loop

RULE THREE:
	The exit condition is:
		* usually "false" the first time through
		* it must be possible to make it "true"
		  in the loop.

	var done: boolean := false
	var s: string 
	
	loop
		exit when done
		get s
		done := 1=0
		put s
	end loop