define various amount fields for the policy_details

1 files changed, 10 insertions, 7 deletions

diff --git a/design-documents/028-deposit-policies.rst b/design-documents/028-deposit-policies.rst
index 62c45170..be840353 100644
--- a/design-documents/028-deposit-policies.rst
+++ b/design-documents/028-deposit-policies.rst
@@ -87,7 +87,7 @@ TODO: Description
                 label=<<B>policy_details</B>>
                 margin=20
                 policy_details [
-                  label="<id>id\l|<hash>hash_code (unique)\l|deadline\l|total_amount\l|policy_fee\l|refresh_amount\l|state\l"
+                  label="<id>id\l|<hash>hash_code (unique)\l|deadline\l|commitment (amount)\l|accumulated_total (amount)\l|fee (amount)\l|transferable (amount)\l|fulfilment_state\l"
                 ]
         }
 
@@ -124,9 +124,10 @@ Ready
         fulfilment to arrive before the deadline.
 
 Insufficient
-        The policy lacks funding, but has otherwise been accepted.  Funding can
-        be continued by calling ``/deposit`` with more coins and the same
-        policy details.
+        The policy lacks funding, that is ``accumulated_total`` <
+        ``commitment``, but has otherwise been accepted.  Funding can be
+        continued by calling ``/deposit`` with more coins and the same policy
+        details.
 
 Success
         The policy is provably fulfilled.  The amounts for payout, fees and
@@ -149,9 +150,11 @@ Invariants
 
 The following invariants need to be fulfilled and be checked by the auditor:
 
-- The total sum of amounts of all deposits that refer the same policy detail
-  MUST NOT be less than the amount in the ``total_amount`` field in the
-  ``policy_details`` table.
+- The fulfilment state of a policy is **Insufficient** IF AND ONLY IF the
+  amount in ``commitment`` is larger than the amount in ``accumulated_total``.
+
+- The sum of amounts in ``fee`` and ``transferable`` must be less or equal to
+  the amount in ``accumulated_total``.
 
 - If the fulfilment state of a policy is **Success**, there MUST exists an
   entry in the ``policy_details_fulfilment`` table for the corresponding