diff --git a/src/bin/svg.rs b/src/bin/svg.rs
index b9a390c..70a40dc 100644
--- a/src/bin/svg.rs
+++ b/src/bin/svg.rs
@@ -14,19 +14,20 @@ const COLORS: &'static [Color] = &[
 ];
 
 fn main() {
+	let vars = [A, B, C];
 	let function = vec![0, 0, 1, 1, 1, 1, 1, 0].into_iter().map(Into::into).collect();
-	let groups = find_groups(&function, &[A, B, C], One);
+	let groups = find_groups(&function, &vars, One);
 	eprintln!("all:");
 	for x in &groups {
 		eprintln!("{}", print_implicant(x));
 	}
 	eprintln!("prime:");
-	let prime = find_prime(&function, &[A, B, C], One, &groups);
+	let prime = find_prime(&function, &vars, One, &groups);
 	for x in &prime {
 		eprintln!("{}", print_implicant(x));
 	}
 	eprintln!("solutions:");
-	let solutions = all_solutions(function.clone(), &[A, B, C], One, &prime, &groups);
+	let solutions = all_solutions(function.clone(), &vars, One, &prime, &groups);
 	for sol in solutions {
 		for x in &prime {
 			eprint!("{} | ", print_implicant(x));
@@ -43,7 +44,7 @@ fn main() {
 
 	let (grid, w, h) = grid(3);
 	println!("{}", BeginSvg { w: w * SIZE_FACTOR + 3, h: h * SIZE_FACTOR + 3 });
-	for (i, (x, y)) in grid.iter().enumerate() {
+	for (i, &(x, y)) in grid.iter().enumerate() {
 		println!("{}",
 			rectangle(1 + x * SIZE_FACTOR, 1 + y * SIZE_FACTOR, SIZE_FACTOR, SIZE_FACTOR)
 				.fill(white())
@@ -51,11 +52,71 @@ fn main() {
 		);
 		let mut rect = rectangle(1 + x * SIZE_FACTOR, 1 + y * SIZE_FACTOR, SIZE_FACTOR, SIZE_FACTOR)
 			.fill(white())
-			.stroke_opacity(0.7);
+			.stroke_opacity(0.7)
+			.inflate(-1, -1);
+		let mut ident = 1;
 		for (idx, &(mask, inv_mask)) in block_masks.iter().enumerate() {
 			rect = rect.inflate(-2, -2);
+			ident += 2;
 			if check_mask(i, mask, inv_mask) {
-				println!("{}", rect.stroke(Stroke::Color(COLORS[idx], 2.0)));
+				// check cells around this one
+				let mut up = false;
+				let mut down = false;
+				let mut left = false;
+				let mut right = false;
+				for &var in &vars {
+					let j = i ^ var;
+					if check_mask(j, mask, inv_mask) {
+						let (x2, y2) = grid[j];
+						if (x + 1) % w == x2 && y == y2 {
+							right = true;
+						}
+						if x == x2 && (y + 1) % h == y2 {
+							down = true;
+						}
+						if x == x2 && y == (y2 + 1) % h {
+							up = true;
+						}
+						if x == (x2 + 1) % w && y == y2 {
+							left = true;
+						}
+						if !up && !down && !left && !right {
+							unreachable!()
+						}
+					}
+				}
+				let mut sides = rect.sides();
+				for s in &mut sides {
+					*s = s.opacity(0.9);
+				}
+				if up {
+					println!("{}", sides[0].width(2.0).color(white()));
+					println!("{}", sides[2].width(2.0).color(COLORS[idx]).offset(0.0, -ident - 1));
+					println!("{}", sides[3].width(2.0).color(COLORS[idx]).offset(0.0, -ident - 1));
+				} else {
+					println!("{}", sides[0].width(2.0).color(COLORS[idx]));
+				}
+				if down {
+					println!("{}", sides[1].width(2.0).color(white()));
+					println!("{}", sides[2].width(2.0).color(COLORS[idx]).offset(0.0, ident + 1));
+					println!("{}", sides[3].width(2.0).color(COLORS[idx]).offset(0.0, ident + 1));
+				} else {
+					println!("{}", sides[1].width(2.0).color(COLORS[idx]));
+				}
+				if left {
+					println!("{}", sides[2].width(2.0).color(white()));
+					println!("{}", sides[0].width(2.0).color(COLORS[idx]).offset(-ident - 1, 0));
+					println!("{}", sides[1].width(2.0).color(COLORS[idx]).offset(-ident - 1, 0));
+				} else {
+					println!("{}", sides[2].width(2.0).color(COLORS[idx]));
+				}
+				if right {
+					println!("{}", sides[3].width(1.0).color(white()));
+					println!("{}", sides[0].width(2.0).color(COLORS[idx]).offset(ident + 1, 0));
+					println!("{}", sides[1].width(2.0).color(COLORS[idx]).offset(ident + 1, 0));
+				} else {
+					println!("{}", sides[3].width(2.0).color(COLORS[idx]));
+				}
 			}
 		}
 		println!("{}",