code checks 2


compiler check for boolean expressions combining 'and' and 'or' without brackets.


	e.g. 	if (a and b or c)


	unambiguous in most languages, subject to misunderstandings though


		same as 
			if ((a and b) or c)



		not the same as


			if (a and (b or c))


		this code leads to different results, possibly very serious bugs

	