diff --git a/src/main.rs b/src/main.rs
index b5302a7..9f06596 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -110,11 +110,11 @@ impl RoyaltyTree {
             self.tree[index].lazy=FiNum::zero();
         } else {
             let lazy=self.tree[index].lazy;
-            let d1=lazy*self.weight_here(index)/self.weight_here_below(index);
+            let d1=if lazy>0.into() { lazy*self.weight_here(index)/self.weight_here_below(index) } else { FiNum::zero() };
             let d02=lazy-d1;
             let index_left =wt_left (index).unwrap();
             let index_right=wt_right(index).unwrap();
-            let d0=d02*self.weight_here_below(index_left)/self.weight_below(index);
+            let d0=if d02>0.into() { d02*self.weight_here_below(index_left)/self.weight_below(index) } else { FiNum::zero() };
             let d2=d02-d0;
             assert!(lazy==d0+d1+d2,"Distributing amounts that don't add up.");
             self.tree[index_left ].lazy+=d0;
@@ -140,19 +140,20 @@ impl RoyaltyTree {
         }
     fn add_weight(&mut self, index: usize, weight: FiNum) {
         println!("Add_weight at {}",index);
-        if self.tree.len()>0 {
+	if self.tree.len()>0 {
             let mut ff0=self.forefather();
-            self.expand_to(wt_forefather(index)*2);
-            let ff=self.forefather();
-            while ff0!=ff {
-                let w=self.tree[ff0].weight;
-                ff0=wt_parent(ff0);
-                self.tree[ff0].weight=w;
-                }
+            let ff1=wt_forefather(index);
+	    let w=self.tree[ff0].weight;
+	    self.expand_to(ff1*2);
+	    while ff0<ff1 {
+	        ff0=wt_parent(ff0);
+		self.tree[ff0].weight=w;
+		}
             }
-        let ff=self.forefather();
+	else { self.expand_to(wt_forefather(index)*2); }
         self.get_royalty(index); // Just for the side effect of capturing everything to this point
         let mut index=index;
+	let ff=self.forefather();
         println!("Ascending from {} to {}",index,ff);
         while index!=ff {
             self.tree[index].weight+=weight;
@@ -503,7 +504,7 @@ fn tree_stuff() {
 
 fn royalty_stuff() {
     let mut rt=RoyaltyTree::new();
-    for index in 0..20 {
+    for index in 0..10 {
         rt.add_weight(index,FiNum::new_i32(10));
         rt.add_royalty(FiNum::new_i32(24))
         }