From b52aa39199524012e7da8b45cc9d7d4ca682e753 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 12:01:31 +0100
Subject: edit req-000

---
 requirements/catalogue/req-000.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-000.md b/requirements/catalogue/req-000.md
index 6f54440..913f592 100644
--- a/requirements/catalogue/req-000.md
+++ b/requirements/catalogue/req-000.md
@@ -1,6 +1,6 @@
 # req-000
 
-As a user, I want my incomings to equal my outgoings in the long run, so that I
-don't go bankrupt.
+As a user, I want my outgoings not to exceed my incomings in the long run, so
+that I don't go bankrupt.
 
-Source: user need.
+Source: need-000.
-- 
cgit v1.2.3


From a76950de620ceb6c9866d3c13a4ac2a6af6a26b5 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 12:02:27 +0100
Subject: req-001 sourced from need-001

---
 requirements/catalogue/req-001.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-001.md b/requirements/catalogue/req-001.md
index 12bef30..3e3cefc 100644
--- a/requirements/catalogue/req-001.md
+++ b/requirements/catalogue/req-001.md
@@ -2,4 +2,4 @@
 
 As a user, I want to control what I do with my money, so that I use money well.
 
-Source: user need.
+Source: need-001.
-- 
cgit v1.2.3


From a1f4f2b216201f9e305dbde65f2d3035684fe423 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 12:05:17 +0100
Subject: add req-025

---
 requirements/catalogue/req-025.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 requirements/catalogue/req-025.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-025.md b/requirements/catalogue/req-025.md
new file mode 100644
index 0000000..b0cacd8
--- /dev/null
+++ b/requirements/catalogue/req-025.md
@@ -0,0 +1,6 @@
+# req-025
+
+As a user, I want my incomings not to exceed my outgoings in the long run, so
+that I can use my money well.
+
+Source: need-001
\ No newline at end of file
-- 
cgit v1.2.3


From c1e92445b17f6042b0bb43e463345aae1d726c26 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 12:49:07 +0100
Subject: fix req-000

---
 requirements/catalogue/req-000.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-000.md b/requirements/catalogue/req-000.md
index 913f592..02ee740 100644
--- a/requirements/catalogue/req-000.md
+++ b/requirements/catalogue/req-000.md
@@ -3,4 +3,4 @@
 As a user, I want my outgoings not to exceed my incomings in the long run, so
 that I don't go bankrupt.
 
-Source: need-000.
+Source: need-000
-- 
cgit v1.2.3


From 7a39eeac6050727b5aa5a8907649df9427aed5b2 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 12:49:35 +0100
Subject: fix req-001

---
 requirements/catalogue/req-001.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-001.md b/requirements/catalogue/req-001.md
index 3e3cefc..2161790 100644
--- a/requirements/catalogue/req-001.md
+++ b/requirements/catalogue/req-001.md
@@ -2,4 +2,4 @@
 
 As a user, I want to control what I do with my money, so that I use money well.
 
-Source: need-001.
+Source: need-001
-- 
cgit v1.2.3


From b334f6ab986c6b9f81f8c1afac709822a349b481 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:00:44 +0100
Subject: add req-026

---
 requirements/catalogue/req-026.md | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 requirements/catalogue/req-026.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-026.md b/requirements/catalogue/req-026.md
new file mode 100644
index 0000000..f74cf18
--- /dev/null
+++ b/requirements/catalogue/req-026.md
@@ -0,0 +1,8 @@
+# req-026
+
+Buckets must have a `name` property, which describes a real-world category of
+spending.
+
+Source: req-017
+
+Satisfied by: dml-bucket
\ No newline at end of file
-- 
cgit v1.2.3


From e4a45be445c7b85b5ab5a2f6addd08336d9e45ee Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:03:05 +0100
Subject: add req-027

---
 requirements/catalogue/req-027.md | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 requirements/catalogue/req-027.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-027.md b/requirements/catalogue/req-027.md
new file mode 100644
index 0000000..83208a7
--- /dev/null
+++ b/requirements/catalogue/req-027.md
@@ -0,0 +1,9 @@
+# req-027
+
+Buckets must have a `balance` property, which represents the amount of money
+currently in the bucket, that is, the difference between the amount of money
+which has flowed in from a pipe less the amount taken out by my transactions.
+
+Source: req-017
+
+Satisfied by: dml-bucket
-- 
cgit v1.2.3


From 3ab0b1a764d9f2bd6745d03cc9bd520c325b115a Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:07:19 +0100
Subject: add req-028

---
 requirements/catalogue/req-002.md |  2 +-
 requirements/catalogue/req-003.md |  2 +-
 requirements/catalogue/req-006.md |  2 +-
 requirements/catalogue/req-028.md | 10 ++++++++++
 4 files changed, 13 insertions(+), 3 deletions(-)
 create mode 100644 requirements/catalogue/req-028.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-002.md b/requirements/catalogue/req-002.md
index 36bc9f8..3d87553 100644
--- a/requirements/catalogue/req-002.md
+++ b/requirements/catalogue/req-002.md
@@ -7,4 +7,4 @@ my money, so that I control what I do with my money.
 
 Source: req-001
 
-Satisfied by: req-003, req-006, req-017, ass-001, ass-002
+Satisfied by: req-028, req-017, ass-002
diff --git a/requirements/catalogue/req-003.md b/requirements/catalogue/req-003.md
index dc746a8..6232329 100644
--- a/requirements/catalogue/req-003.md
+++ b/requirements/catalogue/req-003.md
@@ -5,6 +5,6 @@ spend on beer, so that having buckets and pipes which express how I want to
 distribute, and have previously distributed, my incomings and outgoings enables
 me to control my spending.
 
-Source: req-002
+Source: req-028
 
 Satisfied by: req-004
diff --git a/requirements/catalogue/req-006.md b/requirements/catalogue/req-006.md
index 9b97791..be53d48 100644
--- a/requirements/catalogue/req-006.md
+++ b/requirements/catalogue/req-006.md
@@ -5,6 +5,6 @@ I spend on holidays, so that having buckets and pipes which express how I want
 to distribute, and have previously distributed, my incomings and outgoings
 enables me to control what I do with my money.
 
-Source: req-002
+Source: req-028
 
 Satisfied by: req-007
diff --git a/requirements/catalogue/req-028.md b/requirements/catalogue/req-028.md
new file mode 100644
index 0000000..6832c9e
--- /dev/null
+++ b/requirements/catalogue/req-028.md
@@ -0,0 +1,10 @@
+# req-028
+
+As a user, I want how much money is in my buckets to influence how much I spend
+on the real categories of spending which they represent, so that having buckets
+and pipes which express how I want to distribute, and have previously
+distributed, my incomings and outgoings enables me to control my spending.
+
+Source: req-002
+
+Satisfied by: req-003, req-006, ass-001, req-026, req-027
-- 
cgit v1.2.3


From b449b7eaf90bf795bd0ecfbe8480b98f00af33e5 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:14:38 +0100
Subject: add req-029

---
 requirements/catalogue/req-029.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 requirements/catalogue/req-029.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-029.md b/requirements/catalogue/req-029.md
new file mode 100644
index 0000000..24eb7c1
--- /dev/null
+++ b/requirements/catalogue/req-029.md
@@ -0,0 +1,5 @@
+# req-029
+
+Schist must have an SMS interface for reading the balance of a given bucket.
+
+Source: req-020
\ No newline at end of file
-- 
cgit v1.2.3


From 60e292521fb7a6afbe44d41a0eebb11cfd544848 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:15:02 +0100
Subject: req-020 satisfied by req-024, req-029

---
 requirements/catalogue/req-020.md | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-020.md b/requirements/catalogue/req-020.md
index a745400..cbc5e5e 100644
--- a/requirements/catalogue/req-020.md
+++ b/requirements/catalogue/req-020.md
@@ -5,3 +5,5 @@ that I can know how much money is in my beer bucket when I'm at the bar and I
 have access to my phone.
 
 Source: req-018
+
+Satisfied by: req-024, req-029
-- 
cgit v1.2.3


From bf2722034f0ae8ddc2277894542b8d6eb3b90527 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:48:04 +0100
Subject: add req-030

---
 requirements/catalogue/req-030.md | 47 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 requirements/catalogue/req-030.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-030.md b/requirements/catalogue/req-030.md
new file mode 100644
index 0000000..38961be
--- /dev/null
+++ b/requirements/catalogue/req-030.md
@@ -0,0 +1,47 @@
+# req-030
+
+Schist must implement the procedure described below as `calculate_bucket_balance`.
+
+## calculate_bucket_balance
+
+Inputs:
+
+-   A bucket name, `name`
+
+1. If no bucket exists with the name, `name`, then return empty.
+2. If more than one bucket exists with the name, `name`, then panic.
+3. Let `bucket` be the bucket with the given name.
+4. Let `cache_key = bucket.balance_cache_key`.
+5. Let `is_up_to_date` be the result of the sub-procedure,
+   `is_bucket_balance_up_to_date(bucket)`, as described below.
+6. If `is_up_to_date = TRUE`, then return `bucket.balance`.
+7. Let `transaction_sum` be the sum over the property, `amount`, of all
+   transactions `t` such that `t.bucket_id = bucket.id`.
+8. Let `drip_sum` be the sum over the property, `amount`, of all drips `d` such
+   that `d.bucket_id = bucket.id`.
+9. Return `drip_sum - transaction_sum`.
+
+## is_bucket_balance_up_to_date
+
+Inputs:
+
+-   A bucket, `bucket`
+
+1. Let `cache_key = bucket.balance_cache_key`.
+2. If `cache_key` is not in the format, `<string>:<string>`, then return FALSE.
+3. Let `drip_id` be the part of `cache_key` before the `:`.
+4. If there is no drip with the ID, `drip_id`, then return FALSE.
+5. Let `drip` be the drip with the ID, `drip_id`.
+6. If there is a drip, `drip_2`, such that `drip_2.date > drip.date` and
+   `drip.bucket_id = bucket.id`, then return FALSE.
+7. Let `transaction_id` be the part of `cache_key` after the `:`.
+8. If there is no transaction with the ID, `transaction_id`, then return FALSE.
+9. Let `transaction` be the transaction with the ID, `transaction_id`.
+10. If there is a transaction, `transaction_2`, such that
+    `transaction_2.date > transaction.date` and
+    `transaction.bucket_id = bucket.id`, then return FALSE.
+11. Return TRUE.
+
+Source: req-029
+
+Satisfied by: dml-bucket, dml-drip
-- 
cgit v1.2.3


From 22d62da7584859b92f449aea8f92e48c21459b72 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:52:00 +0100
Subject: edit req-024

---
 requirements/catalogue/req-024.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-024.md b/requirements/catalogue/req-024.md
index 612132f..6b56acc 100644
--- a/requirements/catalogue/req-024.md
+++ b/requirements/catalogue/req-024.md
@@ -1,6 +1,6 @@
 # req-023
 
-As a user, I want Schist to have an accurate record of the balance of my beer
+As a user, I want Schist to be able to infer the accurate balance of my beer
 bucket, so that I can find out my beer balance in Schist using SMS.
 
 Source: req-020
-- 
cgit v1.2.3


From f27abfd486c92c50038336424fc89bf77334ee3c Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:54:58 +0100
Subject: add req-031

---
 requirements/catalogue/req-031.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 requirements/catalogue/req-031.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-031.md b/requirements/catalogue/req-031.md
new file mode 100644
index 0000000..11a2f29
--- /dev/null
+++ b/requirements/catalogue/req-031.md
@@ -0,0 +1,6 @@
+# req-031
+
+Schist must have an SMS interface for the procedure, `calculate_bucket_balance`
+as described in req-030.
+
+Source: req-029
\ No newline at end of file
-- 
cgit v1.2.3


From 30286f8b03a017887f3bfcb4734896f144d44a92 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:56:05 +0100
Subject: add req-032

---
 requirements/catalogue/req-024.md | 2 ++
 requirements/catalogue/req-032.md | 5 +++++
 2 files changed, 7 insertions(+)
 create mode 100644 requirements/catalogue/req-032.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-024.md b/requirements/catalogue/req-024.md
index 6b56acc..5119d3e 100644
--- a/requirements/catalogue/req-024.md
+++ b/requirements/catalogue/req-024.md
@@ -4,3 +4,5 @@ As a user, I want Schist to be able to infer the accurate balance of my beer
 bucket, so that I can find out my beer balance in Schist using SMS.
 
 Source: req-020
+
+Satisfied by: req-032
diff --git a/requirements/catalogue/req-032.md b/requirements/catalogue/req-032.md
new file mode 100644
index 0000000..aa08be1
--- /dev/null
+++ b/requirements/catalogue/req-032.md
@@ -0,0 +1,5 @@
+# req-032
+
+Schist must be able to infer the accurate balance of any given bucket.
+
+Source: req-024
\ No newline at end of file
-- 
cgit v1.2.3


From 3500683722c5290532ec77785fd4ad943450722c Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 13:58:41 +0100
Subject: add req-033

---
 requirements/catalogue/req-033.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 requirements/catalogue/req-033.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-033.md b/requirements/catalogue/req-033.md
new file mode 100644
index 0000000..9df39d2
--- /dev/null
+++ b/requirements/catalogue/req-033.md
@@ -0,0 +1,5 @@
+# req-033
+
+Whenever the user makes a transaction, they must be able to enter it into Schist.
+
+Source: req-032
-- 
cgit v1.2.3


From 59d72b6c6a5f48a49fcbe91fee72eff20b9bb8d3 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 14:03:00 +0100
Subject: add req-034

---
 requirements/catalogue/req-033.md | 2 +-
 requirements/catalogue/req-034.md | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 requirements/catalogue/req-034.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-033.md b/requirements/catalogue/req-033.md
index 9df39d2..fce9092 100644
--- a/requirements/catalogue/req-033.md
+++ b/requirements/catalogue/req-033.md
@@ -2,4 +2,4 @@
 
 Whenever the user makes a transaction, they must be able to enter it into Schist.
 
-Source: req-032
+Source: req-034
diff --git a/requirements/catalogue/req-034.md b/requirements/catalogue/req-034.md
new file mode 100644
index 0000000..d8e2137
--- /dev/null
+++ b/requirements/catalogue/req-034.md
@@ -0,0 +1,5 @@
+# req-034
+
+Schist must have an accurate record of my transactions.
+
+Source: req-032
\ No newline at end of file
-- 
cgit v1.2.3


From af7920c8e9405ea0e7591907555edad3a19688c8 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 14:06:41 +0100
Subject: edit req-030

---
 requirements/catalogue/req-030.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-030.md b/requirements/catalogue/req-030.md
index 38961be..09286df 100644
--- a/requirements/catalogue/req-030.md
+++ b/requirements/catalogue/req-030.md
@@ -38,7 +38,7 @@ Inputs:
 8. If there is no transaction with the ID, `transaction_id`, then return FALSE.
 9. Let `transaction` be the transaction with the ID, `transaction_id`.
 10. If there is a transaction, `transaction_2`, such that
-    `transaction_2.date > transaction.date` and
+    `transaction_2.timestamp >= transaction.timestamp` and
     `transaction.bucket_id = bucket.id`, then return FALSE.
 11. Return TRUE.
 
-- 
cgit v1.2.3


From ea21b9246ca930c88b9092156767b437447b8280 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 14:36:26 +0100
Subject: edit req-030

---
 requirements/catalogue/req-030.md | 2 --
 1 file changed, 2 deletions(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-030.md b/requirements/catalogue/req-030.md
index 09286df..cb27f11 100644
--- a/requirements/catalogue/req-030.md
+++ b/requirements/catalogue/req-030.md
@@ -43,5 +43,3 @@ Inputs:
 11. Return TRUE.
 
 Source: req-029
-
-Satisfied by: dml-bucket, dml-drip
-- 
cgit v1.2.3


From ee6d4d87ffe36fe286e9976a7785a83d0d340c92 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 14:41:01 +0100
Subject: add req-035

---
 requirements/catalogue/req-030.md | 25 ++-----------------------
 requirements/catalogue/req-035.md | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 23 deletions(-)
 create mode 100644 requirements/catalogue/req-035.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-030.md b/requirements/catalogue/req-030.md
index cb27f11..2cb1bdd 100644
--- a/requirements/catalogue/req-030.md
+++ b/requirements/catalogue/req-030.md
@@ -12,8 +12,8 @@ Inputs:
 2. If more than one bucket exists with the name, `name`, then panic.
 3. Let `bucket` be the bucket with the given name.
 4. Let `cache_key = bucket.balance_cache_key`.
-5. Let `is_up_to_date` be the result of the sub-procedure,
-   `is_bucket_balance_up_to_date(bucket)`, as described below.
+5. Let `is_up_to_date` be the result of the procedure,
+   `is_bucket_balance_up_to_date(bucket)`, as described in req-035.
 6. If `is_up_to_date = TRUE`, then return `bucket.balance`.
 7. Let `transaction_sum` be the sum over the property, `amount`, of all
    transactions `t` such that `t.bucket_id = bucket.id`.
@@ -21,25 +21,4 @@ Inputs:
    that `d.bucket_id = bucket.id`.
 9. Return `drip_sum - transaction_sum`.
 
-## is_bucket_balance_up_to_date
-
-Inputs:
-
--   A bucket, `bucket`
-
-1. Let `cache_key = bucket.balance_cache_key`.
-2. If `cache_key` is not in the format, `<string>:<string>`, then return FALSE.
-3. Let `drip_id` be the part of `cache_key` before the `:`.
-4. If there is no drip with the ID, `drip_id`, then return FALSE.
-5. Let `drip` be the drip with the ID, `drip_id`.
-6. If there is a drip, `drip_2`, such that `drip_2.date > drip.date` and
-   `drip.bucket_id = bucket.id`, then return FALSE.
-7. Let `transaction_id` be the part of `cache_key` after the `:`.
-8. If there is no transaction with the ID, `transaction_id`, then return FALSE.
-9. Let `transaction` be the transaction with the ID, `transaction_id`.
-10. If there is a transaction, `transaction_2`, such that
-    `transaction_2.timestamp >= transaction.timestamp` and
-    `transaction.bucket_id = bucket.id`, then return FALSE.
-11. Return TRUE.
-
 Source: req-029
diff --git a/requirements/catalogue/req-035.md b/requirements/catalogue/req-035.md
new file mode 100644
index 0000000..0dc9aaf
--- /dev/null
+++ b/requirements/catalogue/req-035.md
@@ -0,0 +1,27 @@
+# req-035
+
+Schist must implement the procedure described below as
+`is_bucket_balance_up_to_date`.
+
+## is_bucket_balance_up_to_date
+
+Inputs:
+
+-   A bucket, `bucket`
+
+1. Let `cache_key = bucket.balance_cache_key`.
+2. If `cache_key` is not in the format, `<string>:<string>`, then return FALSE.
+3. Let `drip_id` be the part of `cache_key` before the `:`.
+4. If there is no drip with the ID, `drip_id`, then return FALSE.
+5. Let `drip` be the drip with the ID, `drip_id`.
+6. If there is a drip, `drip_2`, such that `drip_2.date > drip.date` and
+   `drip.bucket_id = bucket.id`, then return FALSE.
+7. Let `transaction_id` be the part of `cache_key` after the `:`.
+8. If there is no transaction with the ID, `transaction_id`, then return FALSE.
+9. Let `transaction` be the transaction with the ID, `transaction_id`.
+10. If there is a transaction, `transaction_2`, such that
+    `transaction_2.timestamp >= transaction.timestamp` and
+    `transaction.bucket_id = bucket.id`, then return FALSE.
+11. Return TRUE.
+
+Source: req-030
\ No newline at end of file
-- 
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From f346faadb1433b1aebce97aa3e829910ca5457b2 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 14:43:56 +0100
Subject: add req-036

---
 requirements/catalogue/req-036.md | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 requirements/catalogue/req-036.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-036.md b/requirements/catalogue/req-036.md
new file mode 100644
index 0000000..db3f4dd
--- /dev/null
+++ b/requirements/catalogue/req-036.md
@@ -0,0 +1,7 @@
+# req-036
+
+Given a bucket, `bucket`, if the procedure
+`is_bucket_balance_up_to_date(bucket)` as described in req-035 returns TRUE,
+then the accurate balance of `bucket` is equal to `bucket.balance`.
+
+Sources: req-030, req-032
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-- 
cgit v1.2.3


From 519721cd14e31fcc6998b387a27eaf3ad34d2869 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 15:09:31 +0100
Subject: add req-037

---
 requirements/catalogue/req-030.md |  8 ++++---
 requirements/catalogue/req-035.md |  4 ++--
 requirements/catalogue/req-037.md | 48 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 5 deletions(-)
 create mode 100644 requirements/catalogue/req-037.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-030.md b/requirements/catalogue/req-030.md
index 2cb1bdd..e09a281 100644
--- a/requirements/catalogue/req-030.md
+++ b/requirements/catalogue/req-030.md
@@ -15,10 +15,12 @@ Inputs:
 5. Let `is_up_to_date` be the result of the procedure,
    `is_bucket_balance_up_to_date(bucket)`, as described in req-035.
 6. If `is_up_to_date = TRUE`, then return `bucket.balance`.
-7. Let `transaction_sum` be the sum over the property, `amount`, of all
+7. Carry out the procedure, `update_bucket_drips(bucket)`, as described in
+   req-037.
+8. Let `transaction_sum` be the sum over the property, `amount`, of all
    transactions `t` such that `t.bucket_id = bucket.id`.
-8. Let `drip_sum` be the sum over the property, `amount`, of all drips `d` such
+9.  Let `drip_sum` be the sum over the property, `amount`, of all drips `d` such
    that `d.bucket_id = bucket.id`.
-9. Return `drip_sum - transaction_sum`.
+10. Return `drip_sum - transaction_sum`.
 
 Source: req-029
diff --git a/requirements/catalogue/req-035.md b/requirements/catalogue/req-035.md
index 0dc9aaf..15b797b 100644
--- a/requirements/catalogue/req-035.md
+++ b/requirements/catalogue/req-035.md
@@ -14,8 +14,8 @@ Inputs:
 3. Let `drip_id` be the part of `cache_key` before the `:`.
 4. If there is no drip with the ID, `drip_id`, then return FALSE.
 5. Let `drip` be the drip with the ID, `drip_id`.
-6. If there is a drip, `drip_2`, such that `drip_2.date > drip.date` and
-   `drip.bucket_id = bucket.id`, then return FALSE.
+6. If there is a drip, `drip_2`, such that `drip_2.timestamp > drip.timestamp`
+   and `drip.bucket_id = bucket.id`, then return FALSE.
 7. Let `transaction_id` be the part of `cache_key` after the `:`.
 8. If there is no transaction with the ID, `transaction_id`, then return FALSE.
 9. Let `transaction` be the transaction with the ID, `transaction_id`.
diff --git a/requirements/catalogue/req-037.md b/requirements/catalogue/req-037.md
new file mode 100644
index 0000000..0d27984
--- /dev/null
+++ b/requirements/catalogue/req-037.md
@@ -0,0 +1,48 @@
+# req-037
+
+Schist must implement the procedure, described below as
+`update_budget_drips_for_bucket`.
+
+## update_budget_drips_for_bucket
+
+Inputs:
+
+- A bucket, `bucket`
+
+1. For each pipe `p` such that `p.bucket_id = bucket.id`, carry out the
+   sub-procedure, `update_budget_drips_for_pipe(pipe)`, as described below.
+
+## update_budget_drips_for_pipe
+
+Inputs:
+
+- A pipe, `pipe`
+
+1. Let `prev_drip` be a drip `d` with a most recent value for the property
+   `date` such that `d.pipe_id = pipe.id`
+2. For each calendar date `d` in the range `(prev_drip.date, today]`, insert
+   a new drip for `pipe`:
+   - `bucket_id`: `pipe.bucket_id`
+   - `pipe_id`: `pipe.id`
+   - `date`: `d`
+   - `amount`: the result of the sub-procedure, `pipe_amount_for_day(pipe, d)`
+     as described below
+   - `timestamp`: now as a Unix timestamp
+
+## pipe_amount_for_date
+
+Inputs:
+
+- A pipe, `pipe`
+- A calendar date, `date`
+
+1. If `pipe.period` is `day`, return `pipe.amount`.
+2. If `pipe.period` is `week`, return `pipe.amount ÷ 7`.
+3. Let `days_in_month` be the number of days in the month to which `date`
+   belongs.
+4. If `pipe.period` is `month`, return `pipe.amount ÷ days_in_month`.
+5. Let `days_in_year` be the number of days in the year to which `date` belongs.
+6. If `period` is not `year`, panic.
+7. Return `pipe.amount ÷ days_in_year`.
+
+Source: req-030
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From ec9138b80c6c2dcd03a8e3d0a79ca40e356d28a9 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 15:24:12 +0100
Subject: add req-038

---
 requirements/catalogue/req-038.md | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 requirements/catalogue/req-038.md

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-038.md b/requirements/catalogue/req-038.md
new file mode 100644
index 0000000..e69de29
-- 
cgit v1.2.3


From 13ed038841fbfd7fb4f6baef00a55fbd22af21e5 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 15:24:20 +0100
Subject: add req-038

---
 requirements/catalogue/req-038.md | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-038.md b/requirements/catalogue/req-038.md
index e69de29..71b8d55 100644
--- a/requirements/catalogue/req-038.md
+++ b/requirements/catalogue/req-038.md
@@ -0,0 +1,6 @@
+# req-038
+
+Schist must have a record of pipes which accurately reflect how I want to
+distribute my incomings and outgoings.
+
+Source: req-032
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-- 
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From 376e5623ef0a202c391908a7a3093df4d804a052 Mon Sep 17 00:00:00 2001
From: Joe Carstairs <jcarstairs@scottlogic.com>
Date: Tue, 15 Jul 2025 17:30:35 +0100
Subject: rework

---
 requirements/catalogue/req-002.md |  2 --
 requirements/catalogue/req-003.md |  9 +++++----
 requirements/catalogue/req-004.md |  7 ++++---
 requirements/catalogue/req-005.md |  3 ++-
 requirements/catalogue/req-018.md |  7 ++++---
 requirements/catalogue/req-019.md |  7 ++++---
 requirements/catalogue/req-020.md |  5 +++--
 requirements/catalogue/req-024.md |  3 ++-
 requirements/catalogue/req-028.md | 10 ++++++----
 requirements/catalogue/req-029.md |  4 +++-
 requirements/catalogue/req-032.md |  8 ++++++--
 requirements/catalogue/req-034.md |  4 +++-
 12 files changed, 42 insertions(+), 27 deletions(-)

(limited to 'requirements/catalogue')

diff --git a/requirements/catalogue/req-002.md b/requirements/catalogue/req-002.md
index 3d87553..55fcb43 100644
--- a/requirements/catalogue/req-002.md
+++ b/requirements/catalogue/req-002.md
@@ -6,5 +6,3 @@ and I want having such buckets and pipes to enable me to control what I do with
 my money, so that I control what I do with my money.
 
 Source: req-001
-
-Satisfied by: req-028, req-017, ass-002
diff --git a/requirements/catalogue/req-003.md b/requirements/catalogue/req-003.md
index 6232329..0ec877e 100644
--- a/requirements/catalogue/req-003.md
+++ b/requirements/catalogue/req-003.md
@@ -1,9 +1,10 @@
 # req-003
 
-As a user, I want how much money is in my beer bucket to influence how much I
-spend on beer, so that having buckets and pipes which express how I want to
-distribute, and have previously distributed, my incomings and outgoings enables
-me to control my spending.
+As a user, given I have a beer bucket and pipes which express how much I want
+to spend on beer, I want how much money is in my beer bucket to influence how
+much I spend on beer, so that having buckets and pipes which express how I want
+to distribute, and have previously distributed, my incomings and outgoings
+enables me to control my spending.
 
 Source: req-028
 
diff --git a/requirements/catalogue/req-004.md b/requirements/catalogue/req-004.md
index e28a256..e39e58a 100644
--- a/requirements/catalogue/req-004.md
+++ b/requirements/catalogue/req-004.md
@@ -1,8 +1,9 @@
 # req-004
 
-As a user, I want to consider how much money is in my beer bucket when I decide
-how much to spend on beer at the bar, so that how much money is in my beer
-bucket influences how much I spend on beer.
+As a user, given I have a beer bucket and pipes which express how much I want to
+spend on beer, I want to consider how much money is in my beer bucket when I
+decide how much to spend on beer at the bar, so that how much money is in my
+beer bucket influences how much I spend on beer.
 
 Source: req-003
 
diff --git a/requirements/catalogue/req-005.md b/requirements/catalogue/req-005.md
index 79f00c7..523c285 100644
--- a/requirements/catalogue/req-005.md
+++ b/requirements/catalogue/req-005.md
@@ -1,6 +1,7 @@
 # req-005
 
-As a user, I want to know how much money is in my beer bucket when I'm at the
+As a user, given I have a beer bucket and pipes which express how much I want to
+spend on beer, I want to know how much money is in my beer bucket when I'm at the
 bar, so that I can consider how much money is in my beer bucket when I decide
 how much to spend on beer at the bar.
 
diff --git a/requirements/catalogue/req-018.md b/requirements/catalogue/req-018.md
index 9b9db42..225fc5d 100644
--- a/requirements/catalogue/req-018.md
+++ b/requirements/catalogue/req-018.md
@@ -1,8 +1,9 @@
 # req-018
 
-As a user, I want to know how much money is in my beer bucket when I'm at the
-bar and I have access to my phone, so that I can know how much money is in my
-beer bucket when I'm at the bar.
+As a user, given I have a beer bucket and pipes which express how much I want
+to spend on beer, I want to know how much money is in my beer bucket when I'm at
+the bar and I have access to my phone, so that I can know how much money is in
+my beer bucket when I'm at the bar.
 
 Source: req-005
 
diff --git a/requirements/catalogue/req-019.md b/requirements/catalogue/req-019.md
index a4d908a..35a7162 100644
--- a/requirements/catalogue/req-019.md
+++ b/requirements/catalogue/req-019.md
@@ -1,8 +1,9 @@
 # req-019
 
-As a user, I want to know how much money is in my beer bucket when I'm at the
-bar and I don't have access to my phone, so that I can know how much money is
-in my beer bucket when I'm at the bar.
+As a user, given I have a beer bucket and pipes which express how much I want to
+spend on beer, I want to know how much money is in my beer bucket when I'm at
+the bar and I don't have access to my phone, so that I can know how much money
+is in my beer bucket when I'm at the bar.
 
 Source: req-005
 
diff --git a/requirements/catalogue/req-020.md b/requirements/catalogue/req-020.md
index cbc5e5e..1e3eeb0 100644
--- a/requirements/catalogue/req-020.md
+++ b/requirements/catalogue/req-020.md
@@ -1,7 +1,8 @@
 # req-020
 
-As a user, I want to find out my beer bucket balance in Schist using SMS, so
-that I can know how much money is in my beer bucket when I'm at the bar and I
+As a user, given I have a beer bucket and pipes which express how much I want
+to spend on beer, I want to find out my beer bucket balance in Schist using SMS,
+so that I can know how much money is in my beer bucket when I'm at the bar and I
 have access to my phone.
 
 Source: req-018
diff --git a/requirements/catalogue/req-024.md b/requirements/catalogue/req-024.md
index 5119d3e..efbc3a6 100644
--- a/requirements/catalogue/req-024.md
+++ b/requirements/catalogue/req-024.md
@@ -1,6 +1,7 @@
 # req-023
 
-As a user, I want Schist to be able to infer the accurate balance of my beer
+As a user, given I have a beer bucket and pipes which express how much I want to
+spend on beer, I want Schist to be able to infer the accurate balance of my beer
 bucket, so that I can find out my beer balance in Schist using SMS.
 
 Source: req-020
diff --git a/requirements/catalogue/req-028.md b/requirements/catalogue/req-028.md
index 6832c9e..e86c525 100644
--- a/requirements/catalogue/req-028.md
+++ b/requirements/catalogue/req-028.md
@@ -1,9 +1,11 @@
 # req-028
 
-As a user, I want how much money is in my buckets to influence how much I spend
-on the real categories of spending which they represent, so that having buckets
-and pipes which express how I want to distribute, and have previously
-distributed, my incomings and outgoings enables me to control my spending.
+As a user, given my buckets and pipes express how I want to distribute my
+incomings and outgoings, I want how much money is in my buckets to influence
+how much I spend on the real categories of spending which they represent, so
+that having buckets and pipes which express how I want to distribute, and have
+previously distributed, my incomings and outgoings enables me to control my
+spending.
 
 Source: req-002
 
diff --git a/requirements/catalogue/req-029.md b/requirements/catalogue/req-029.md
index 24eb7c1..26bf701 100644
--- a/requirements/catalogue/req-029.md
+++ b/requirements/catalogue/req-029.md
@@ -1,5 +1,7 @@
 # req-029
 
-Schist must have an SMS interface for reading the balance of a given bucket.
+Given the user's buckets and pipes express how the user wants to distribute
+their incomings and outgoings, Schist must have an SMS interface for a
+procedure which returns the accurate balance of a given bucket.
 
 Source: req-020
\ No newline at end of file
diff --git a/requirements/catalogue/req-032.md b/requirements/catalogue/req-032.md
index aa08be1..6f173ac 100644
--- a/requirements/catalogue/req-032.md
+++ b/requirements/catalogue/req-032.md
@@ -1,5 +1,9 @@
 # req-032
 
-Schist must be able to infer the accurate balance of any given bucket.
+Given the user's buckets and pipes express how the user wants to distribute
+their incomings and outgoings, Schist must be able to infer the accurate balance
+of any given bucket.
 
-Source: req-024
\ No newline at end of file
+Source: req-024
+
+Satisfied by: req-030, req-034, ass-008, req-036
\ No newline at end of file
diff --git a/requirements/catalogue/req-034.md b/requirements/catalogue/req-034.md
index d8e2137..9971dd2 100644
--- a/requirements/catalogue/req-034.md
+++ b/requirements/catalogue/req-034.md
@@ -2,4 +2,6 @@
 
 Schist must have an accurate record of my transactions.
 
-Source: req-032
\ No newline at end of file
+Source: req-032
+
+Satisfied by: req-033, ass-009
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