Update neps/nep-0536.md

Co-authored-by: Michael Birch <birchmd8@gmail.com>

neps/nep-0536.md

@@ -36,7 +36,7 @@ and creating unnecessary refunds. Some examples:
 
 The protocol changes are as follows:
 * When a transaction is converted to a receipt, there is no longer a `pessmistic_gas_price` multiplier when the signer balance is deducted. Instead, the signer is charged `transaction_gas_cost * gas_price`. If the transaction succeeds, then unless the transaction contains a function call action, it will not generate any refund. On the other hand, when a transaction with multiple action fails, there is gas refund for the rest of unexecuted actions, same as how the protocol works today.
-* For function calls, if X gas is attached during the execution of a receipt and Y gas is burnt, then `max(0, X-Y-refund_cost)` is refunded at the original gas price where `refund_cost = max(REFUND_FIXED_COST, 0.05 * X-Y)`.
+* For function calls, if X gas is attached during the execution of a receipt and Y gas is used+burnt, then `max(0, X-Y-refund_cost)` is refunded at the original gas price where `refund_cost = max(REFUND_FIXED_COST, 0.05 * X-Y)`. In the case the refund is 0 then no refund receipt is generated.
 * Tokens burnt on refund cost is counted towards tx_balance_burnt and the part over `REFUND_FIXED_COST` is not counted towards gas limit to avoid artificially limiting throughput.
 * Because refund cost is now separate, action costs do not need to account for refund and therefore should be recalculated and reduced.