# slices of boolean matrix
resource slice1()
	op print(bool x[1:*])
	proc print(x)  {
		for [ i = lb(x) to ub(x) ] {
# do it this way to exercise compiler
# -- it previously had problems with x[i] in conditional.
			if (x[i]) { put("T")
			} else { put("F")
			}
		}
		write()
	}
	bool  b[1:4,1:3] 
	for [ r = lb1(b) to ub1(b), c = lb2(b) to ub2(b) ] {
		b[r,c] = r > c
	}
	write("b by rows:")
	for [ r = lb1(b) to ub1(b) ] {
		print( b[r,lb2(b):ub2(b)] )
	}
	bool  bb[1:5,1:4] 
	for [ r = lb1(bb) to ub1(bb), c = lb2(bb) to ub2(bb) ] {
		bb[r,c] = (r+c) % 2 == 0
	}
	write("bb by rows:")
	for [ r = lb1(bb) to ub1(bb) ] {
		print( bb[r,lb2(bb):ub2(bb)] )
	}
end