Rule: open squares can only be mines
	***
	*x*
	***
	(= 	star-unknown-count
		(- x star-mine-count))
=>
	mark-stars



Rule: open squares can't be mines
	***
	*x*
	***
	(= star-mine-count x)
=>
	click-stars



Rule: interface
	***
	*y*
	$$$
	#x#
	###
	(= (- (- x x-mine-count)
	       pound-unknown-count)
		(- y y-mine-count))
=>
	click-stars
	mark-pounds


Rule: short interface
	***$
	*y*$
	*$$#
	$#x#
	$###
	(= (- (- x x-mine-count)
	       pound-unknown-count)
		(- y y-mine-count))
=>
	click-stars
	mark-pounds


Rule: side regions

	#$$*
	#xy*
	#$$*
	(= (- x x-mine-count)
	 
	    (- 	(- y y-mine-count)
	 	star-unknown-count))

=>
	mark-stars
	click-pounds


Rule: corner-tip

	$$$*
	+xy#
	++z#
	+++#

	(=
		(+ (- x x-mine-count)
	   	   (- z z-mine-count))
	    	(- (- y y-mine-count) 1))

=>
	mark-stars


Rule: corner-edge

	$**+
	+xy*
	++z*
	+++#

	(=
		(+ (- x x-mine-count)
	   	   (- z z-mine-count))
	    	(- y y-mine-count))

=>
	click-dollars
	click-pounds