resource bool2()
	bool  r1,r2

	bool  b, c 
	b = true
	c = false
	b = c & ~b | false
	write(b,c)
	r1 = true
	r2 = false
	write( r2 & r1 | false xor (r2 | r1 | false | r2) )
	b = true
	c = false
	r1 = true
	r2 = true
	write( c & b| false )
	write( b xor c, b xor r1, r1 & r2, b | r2 & c, r2 & c | b )
end