Update TIP-109.md

TIPs/TIP-109.md

@@ -28,12 +28,13 @@ Per previously established rules, a Parlay can not have a position on a single g
 `public address parentMarket;`  
 
 2. A double chance market is created automatically through Manager create method whenever a single match market is created
+3. The method `availableToBuyFromAmm` should return the minimum of the available to buy of the two underlying positions
 
-3. Methods buyFromAMM and buyFromAMMQuote in SportsAMM calculate the price of the double chance position by summing up the price for the two individual positions.  
-4. BuyPriceImpact is calculated by adding the two individual BuyPriceImpacts and dividing it by 2  
-5. On buyFromAMM if someone is buying e.g. 1000 1X position (home team not to lose_, the user gets back 1000 tokens deemed HOME from the isDoubleChance marketa. 1000 `1` and 1000 `X` options are sent to DoubleChance market. SportsAMM keeps 1000 options of position `2` (AWAY).  
-6. DoubleChance markets dont need an explicit resolve as they will read the result from the parent market
-7. On Exercise the DoubleChance market will call exercize of underlying individual positions  
+4. Methods buyFromAMM and buyFromAMMQuote in SportsAMM calculate the price of the double chance position by summing up the price for the two individual positions.  
+5. BuyPriceImpact is calculated by adding the two individual BuyPriceImpacts and dividing it by 2  
+6. On buyFromAMM if someone is buying e.g. 1000 1X position (home team not to lose_, the user gets back 1000 tokens deemed HOME from the isDoubleChance marketa. 1000 `1` and 1000 `X` options are sent to DoubleChance market. SportsAMM keeps 1000 options of position `2` (AWAY).  
+7. DoubleChance markets dont need an explicit resolve as they will read the result from the parent market
+8. On Exercise the DoubleChance market will call exercize of underlying individual positions  
 
 
 Selling to the AMM will not be supported for these markets.