From 6b8471f9cc0c2fa0f9b9c4bce52df0314d42984e Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Thu, 26 Mar 2026 16:31:57 +0100
Subject: [PATCH 1/9] spec: recursively compute chip interaction count

---
 spec/chip.typ | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/spec/chip.typ b/spec/chip.typ
index f3ac28a74..78d7386e2 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -24,6 +24,49 @@
   .sum()
 }
 
+#let set_nr_interactions(chip) = {
+  let constraints = chip
+    .constraints
+    .values()
+    .flatten()
+
+  // nr. of direct interactions
+  let nr-direct-interactions = constraints
+    .filter(c=>c.kind == "interaction")
+    .map(c => {
+      let x = c.at("iter", default: (0, 0, 0))
+      x.at(2) - x.at(1) + 1
+    })
+    .sum(default: 0)
+  
+  let template-constraints = constraints.filter(c=>c.kind == "template")
+
+  context {
+    let lookup-table = query(<interaction_count>).map(x => x.value).sum(default:(:))
+
+    // nr. of indirect interactions through templates
+    let nr-indirect-interactions = template-constraints
+      .map(c => {
+        let x = c.at("iter", default: (0, 0, 0))
+        let iter-size = x.at(2) - x.at(1) + 1
+
+        let template-interactions = lookup-table.at(c.tag, default: 0)
+        iter-size * template-interactions 
+      })
+      .sum(default: 0)
+
+    let total-nr-interactions = nr-direct-interactions + nr-indirect-interactions
+
+    [#metadata((chip.name: total-nr-interactions)) <interaction_count>]
+  }
+}
+
+#let get_nr_interactions(chip) = {
+  context {
+    query(<interaction_count>).map(c=>c.value).sum().at(chip.name)
+  }
+}
+
 // Return a list of iterators needed by `obj`. Taken from `iters` or `iter`.
 // Prepend `name` to every iterator, if given.
 #let iters_of(obj, name: none) = {

From 9c18a2a580e11c8222f8b99af776b3d1637399a0 Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Thu, 26 Mar 2026 16:32:39 +0100
Subject: [PATCH 2/9] spec: print interaction count per chip

---
 spec/add.typ    |  6 +++++-
 spec/branch.typ |  6 +++++-
 spec/cpu.typ    |  6 +++++-
 spec/dvrm.typ   |  7 +++++--
 spec/ecall.typ  | 10 ++++++++--
 spec/is_bit.typ |  5 ++++-
 spec/load.typ   |  6 +++++-
 spec/lt.typ     |  6 +++++-
 spec/memw.typ   | 14 +++++++++++---
 spec/mul.typ    |  6 +++++-
 spec/neg.typ    |  6 +++++-
 spec/shift.typ  |  6 +++++-
 spec/sign.typ   |  8 +++++---
 13 files changed, 73 insertions(+), 19 deletions(-)

diff --git a/spec/add.typ b/spec/add.typ
index d2afb1788..a678893e5 100644
--- a/spec/add.typ
+++ b/spec/add.typ
@@ -1,12 +1,15 @@
 #import "/book.typ": book-page, et
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table
+#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table, set_nr_interactions, get_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/add.toml", config)
 
 #show: book-page(chip.name)
 
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
+
 #let add = raw(chip.name)
 #let sub = raw("SUB")
 
@@ -19,6 +22,7 @@ in both conditional and unconditional versions.
 It constrains that $#`diff` equiv #`lhs` - #`rhs` (mod 2^64)$ when the expression `cond` is non-zero.
 
 = Variables
+This template introduces #nr_interactions interaction(s).
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/branch.typ b/spec/branch.typ
index 90503e862..c6bb9254e 100644
--- a/spec/branch.typ
+++ b/spec/branch.typ
@@ -3,6 +3,8 @@
 #import "/chip.typ": (
   render_chip_assumptions,
   render_chip_column_table,
+  set_nr_interactions,
+  get_nr_interactions,
   total_nr_variables,
   total_nr_instantiated_columns,
   render_constraint_table,
@@ -20,8 +22,10 @@ The #branch chip computes the target address of a branching instruction.
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `BRANCH` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `BRANCH` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/cpu.typ b/spec/cpu.typ
index 08fe1533d..16fa4545b 100644
--- a/spec/cpu.typ
+++ b/spec/cpu.typ
@@ -5,6 +5,8 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
+  set_nr_interactions,
+  get_nr_interactions,
   render_constraint_table,
   render_chip_padding_table,
 )
@@ -21,8 +23,10 @@ It bases its decisions on the entry of the `DECODE` table (@decode) correspondin
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `CPU` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `CPU` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/dvrm.typ b/spec/dvrm.typ
index 920aec075..a42f8dff6 100644
--- a/spec/dvrm.typ
+++ b/spec/dvrm.typ
@@ -4,12 +4,13 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
+  set_nr_interactions,
+  get_nr_interactions,
   render_constraint_table,
   render_chip_padding_table,
   render_chip_assumptions
 )
 
-
 #let config = load_config()
 #let chip = load_chip("src/dvrm.toml", config)
 
@@ -22,8 +23,10 @@ The #dvrm chip provides division and remainder functionality, both signed and un
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `DVRM` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `DVRM` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/ecall.typ b/spec/ecall.typ
index 3b82019db..754172bac 100644
--- a/spec/ecall.typ
+++ b/spec/ecall.typ
@@ -4,6 +4,8 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
+  set_nr_interactions,
+  get_nr_interactions,
   render_constraint_table,
   render_chip_assumptions,
   render_chip_padding_table,
@@ -32,8 +34,10 @@ where `A0`-`A7` are symbolic names for the registers `x10`-`x17`
 == Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_halt_interactions = get_nr_interactions(chip)
 
-The #halt chip leverages #nr_variables variable, spanning #nr_columns columns:
+The #halt chip leverages #nr_variables variable, spanning #nr_columns columns and leverages #nr_halt_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 == Assumptions
@@ -76,8 +80,10 @@ As such, no padding is defined.
 == Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_commit_interactions = get_nr_interactions(chip)
 
-The #commit chip leverages #nr_variables variables, spanning #nr_columns columns:
+The #commit chip leverages #nr_variables variables, spanning #nr_columns columns and leverages #nr_commit_interactions interactions:
 #render_chip_column_table(chip, config)
 
 == Constraints
diff --git a/spec/is_bit.typ b/spec/is_bit.typ
index b09242fe4..bb2690afc 100644
--- a/spec/is_bit.typ
+++ b/spec/is_bit.typ
@@ -1,12 +1,15 @@
 #import "/book.typ": book-page
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table, render_constraint_table
+#import "/chip.typ": render_chip_column_table, render_constraint_table, set_nr_interactions, get_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/is_bit.toml", config)
 
 #show: book-page(chip.name)
 
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
+
 #let is_bit = raw(chip.name)
 
 #is_bit is a constraint template that is used to assert that a variable lies in the range ${0, 1}$ if some second variable is non-zero.
diff --git a/spec/load.typ b/spec/load.typ
index b12e1c04d..a486e83cf 100644
--- a/spec/load.typ
+++ b/spec/load.typ
@@ -5,6 +5,8 @@
   render_chip_column_table,
   render_chip_padding_table,
   render_constraint_table,
+  set_nr_interactions,
+  get_nr_interactions,
   total_nr_instantiated_columns,
   total_nr_variables,
 )
@@ -21,8 +23,10 @@ It delegates low-level memory handling to the `MEMW` chip (@memw).
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `LOAD` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `LOAD` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/lt.typ b/spec/lt.typ
index 8e55b390b..433abac18 100644
--- a/spec/lt.typ
+++ b/spec/lt.typ
@@ -7,6 +7,8 @@
   render_constraint_table,
   total_nr_instantiated_columns,
   total_nr_variables,
+  set_nr_interactions,
+  get_nr_interactions,
 )
 
 #let config = load_config()
@@ -20,8 +22,10 @@ The #lt chip constrains an indicator bit for the less-than relation, signed or u
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `LT` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `LT` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/memw.typ b/spec/memw.typ
index 1c7a1e6e5..49aff8a4d 100644
--- a/spec/memw.typ
+++ b/spec/memw.typ
@@ -5,6 +5,8 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
+  set_nr_interactions,
+  get_nr_interactions,
   render_constraint_table,
   render_chip_padding_table
 )
@@ -24,8 +26,10 @@ in order to satisfy the design of the memory argument (@memory).
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_memw_interactions = get_nr_interactions(chip)
 
-The `MEMW` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `MEMW` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_memw_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
@@ -73,6 +77,8 @@ The table can be padded to the next power of two with the following value assign
 
 #let alignedchip = load_chip("src/memw_aligned.toml", config)
 #let aligned = raw(alignedchip.name)
+#set_nr_interactions(alignedchip)
+#let nr_aligned_interactions = get_nr_interactions(alignedchip)
 
 When a memory access happens at an address with proper alignment for its access size
 (i.e., adding the access size to `base_address`'s lowest limb does not overflow), 
@@ -87,7 +93,7 @@ Further logic remains essentially the same, so we briefly present the relevant t
 #let nr_variables = total_nr_variables(alignedchip)
 #let nr_columns = total_nr_instantiated_columns(alignedchip, config)
 
-The #aligned chip only needs #nr_variables variables, expressed through #nr_columns columns.
+The #aligned chip only needs #nr_variables variables, expressed through #nr_columns columns; it leverages #nr_aligned_interactions interactions.
 #render_chip_column_table(alignedchip, config)
 #render_chip_assumptions(alignedchip, config)
 #render_constraint_table(alignedchip, config)
@@ -119,8 +125,10 @@ Note moreover that this chip does not guard against misaligned register access f
 == Columns
 #let nr_variables = total_nr_variables(register_chip)
 #let nr_columns = total_nr_instantiated_columns(register_chip, config)
+#set_nr_interactions(register_chip)
+#let nr_memw_r_interactions = get_nr_interactions(register_chip)
 
-The #reg chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The #reg chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_memw_r_interactions interactions:
 #render_chip_column_table(register_chip, config)
 
 == Assumptions
diff --git a/spec/mul.typ b/spec/mul.typ
index 68ab4a2b8..de4cc6fa3 100644
--- a/spec/mul.typ
+++ b/spec/mul.typ
@@ -4,6 +4,8 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
+  set_nr_interactions,
+  get_nr_interactions,
   render_constraint_table,
   render_chip_assumptions,
   render_chip_padding_table,
@@ -22,8 +24,10 @@ as well as providing access to the low and high halfs of the multiplication resu
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `MUL` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `MUL` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 #let stackrel(top, bottom) = {
diff --git a/spec/neg.typ b/spec/neg.typ
index d700892cb..bcab35cbf 100644
--- a/spec/neg.typ
+++ b/spec/neg.typ
@@ -1,17 +1,21 @@
 #import "/book.typ": book-page, et
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table
+#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table, set_nr_interactions, get_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/neg.toml", config)
 #show: book-page(chip.name)
 
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
+
 #let neg = raw(chip.name)
 
 #neg is a constraint template that is used to assert that $#`neg` = -#`x`$, under the condition that `cond` is non-zero.
 It requires `cond` to be a bit.
 
 = Variables
+This template introduces #nr_interactions interaction(s).
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/shift.typ b/spec/shift.typ
index 289ade1d7..3b3478705 100644
--- a/spec/shift.typ
+++ b/spec/shift.typ
@@ -4,6 +4,8 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
+  set_nr_interactions,
+  get_nr_interactions,
   render_constraint_table,
   render_chip_assumptions,
   render_chip_padding_table,
@@ -36,8 +38,10 @@ Here, `<<` and `>>` denote the _logical_ left and right shift operations, while
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
 
-The `SHIFT` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns:
+The `SHIFT` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/sign.typ b/spec/sign.typ
index 7135ba9c6..06e766d5f 100644
--- a/spec/sign.typ
+++ b/spec/sign.typ
@@ -1,19 +1,21 @@
 #import "/book.typ": book-page
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table,   render_chip_assumptions, render_constraint_table
-
+#import "/chip.typ": render_chip_column_table,   render_chip_assumptions, render_constraint_table, set_nr_interactions, get_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/sign.toml", config)
 #show: book-page(chip.name)
 
+#set_nr_interactions(chip)
+#let nr_interactions = get_nr_interactions(chip)
+
 #let sign = raw(chip.name)
 
 #sign is a constraint template that is used to extract a `Half`word's sign.
 It constrains that `sign` is set to `1` when both `X`'s most significant bit and `signed` are $1$, and $0$ otherwise.
 
 = Variables
-The #sign template operates on three variables:
+The #sign template operates on three variables and introduces #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions

From 0ec9f7473b0d7a05325941505bae7054d86dd235 Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Thu, 26 Mar 2026 16:34:24 +0100
Subject: [PATCH 3/9] spec: cleanup

---
 spec/branch.typ | 2 +-
 spec/cpu.typ    | 2 +-
 spec/dvrm.typ   | 2 +-
 spec/load.typ   | 2 +-
 spec/lt.typ     | 2 +-
 spec/memw.typ   | 2 +-
 spec/mul.typ    | 2 +-
 7 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/spec/branch.typ b/spec/branch.typ
index c6bb9254e..6a4d4feb1 100644
--- a/spec/branch.typ
+++ b/spec/branch.typ
@@ -25,7 +25,7 @@ The #branch chip computes the target address of a branching instruction.
 #set_nr_interactions(chip)
 #let nr_interactions = get_nr_interactions(chip)
 
-The `BRANCH` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
+The #branch chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/cpu.typ b/spec/cpu.typ
index 16fa4545b..715b9d64d 100644
--- a/spec/cpu.typ
+++ b/spec/cpu.typ
@@ -26,7 +26,7 @@ It bases its decisions on the entry of the `DECODE` table (@decode) correspondin
 #set_nr_interactions(chip)
 #let nr_interactions = get_nr_interactions(chip)
 
-The `CPU` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
+The #cpu chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/dvrm.typ b/spec/dvrm.typ
index a42f8dff6..9a420d056 100644
--- a/spec/dvrm.typ
+++ b/spec/dvrm.typ
@@ -26,7 +26,7 @@ The #dvrm chip provides division and remainder functionality, both signed and un
 #set_nr_interactions(chip)
 #let nr_interactions = get_nr_interactions(chip)
 
-The `DVRM` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
+The #dvrm chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/load.typ b/spec/load.typ
index a486e83cf..8d1f61fdc 100644
--- a/spec/load.typ
+++ b/spec/load.typ
@@ -26,7 +26,7 @@ It delegates low-level memory handling to the `MEMW` chip (@memw).
 #set_nr_interactions(chip)
 #let nr_interactions = get_nr_interactions(chip)
 
-The `LOAD` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
+The #load chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/lt.typ b/spec/lt.typ
index 433abac18..763227e53 100644
--- a/spec/lt.typ
+++ b/spec/lt.typ
@@ -25,7 +25,7 @@ The #lt chip constrains an indicator bit for the less-than relation, signed or u
 #set_nr_interactions(chip)
 #let nr_interactions = get_nr_interactions(chip)
 
-The `LT` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
+The #lt chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/memw.typ b/spec/memw.typ
index 49aff8a4d..2a77287b6 100644
--- a/spec/memw.typ
+++ b/spec/memw.typ
@@ -29,7 +29,7 @@ in order to satisfy the design of the memory argument (@memory).
 #set_nr_interactions(chip)
 #let nr_memw_interactions = get_nr_interactions(chip)
 
-The `MEMW` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_memw_interactions interaction(s):
+The #memw chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_memw_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 = Assumptions
diff --git a/spec/mul.typ b/spec/mul.typ
index de4cc6fa3..77d1cca43 100644
--- a/spec/mul.typ
+++ b/spec/mul.typ
@@ -27,7 +27,7 @@ as well as providing access to the low and high halfs of the multiplication resu
 #set_nr_interactions(chip)
 #let nr_interactions = get_nr_interactions(chip)
 
-The `MUL` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
+The #mul chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
 
 #let stackrel(top, bottom) = {

From 1d8eb8ee38efaef3794d27115329d0752e071ef2 Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Tue, 31 Mar 2026 15:03:54 +0200
Subject: [PATCH 4/9] spec/interaction-counter: add multi-dimensional iter
 support

---
 spec/chip.typ | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/spec/chip.typ b/spec/chip.typ
index 78d7386e2..0339b7912 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -24,6 +24,26 @@
   .sum()
 }
 
+// Given a constraint, compute the number of interactions it induces
+#let get_interaction_count(constraint) = {
+  let iters = if "iters" in constraint {
+    constraint.iters
+  } else if "iter" in constraint {
+    (constraint.iter,)
+  } else {
+    ()
+  }
+
+  iters.map(i => {
+    assert(
+      i.len() == 3 and type(i.at(1)) == int and type(i.at(2)) == int,
+      message: "contains invalid iter: " + repr(i),
+    )
+    i.at(2) - i.at(1) + 1
+  })
+  .product(default: 1)
+}
+
 #let set_nr_interactions(chip) = {
   let constraints = chip
     .constraints
@@ -33,10 +53,7 @@
   // nr. of direct interactions
   let nr-direct-interactions = constraints
     .filter(c=>c.kind == "interaction")
-    .map(c => {
-      let x = c.at("iter", default: (0, 0, 0))
-      x.at(2) - x.at(1) + 1
-    })
+    .map(get_interaction_count)
     .sum(default: 0)
   
   let template-constraints = constraints.filter(c=>c.kind == "template")
@@ -47,10 +64,9 @@
     // nr. of indirect interactions through templates
     let nr-indirect-interactions = template-constraints
       .map(c => {
-        let x = c.at("iter", default: (0, 0, 0))
-        let iter-size = x.at(2) - x.at(1) + 1
-
+        let iter-size = get_interaction_count(c)
         let template-interactions = lookup-table.at(c.tag, default: 0)
+
         iter-size * template-interactions 
       })
       .sum(default: 0)

From 29a2581389e3c195ba77f1161e172e776f46af5a Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Tue, 31 Mar 2026 15:15:10 +0200
Subject: [PATCH 5/9] spec/interaction-counter: count SUB interactions

---
 spec/add.typ  |  1 +
 spec/chip.typ | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/spec/add.typ b/spec/add.typ
index a678893e5..a41fd37b8 100644
--- a/spec/add.typ
+++ b/spec/add.typ
@@ -8,6 +8,7 @@
 #show: book-page(chip.name)
 
 #set_nr_interactions(chip)
+#set_nr_interactions(chip, name: "SUB")
 #let nr_interactions = get_nr_interactions(chip)
 
 #let add = raw(chip.name)
diff --git a/spec/chip.typ b/spec/chip.typ
index 0339b7912..eb65c5128 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -44,7 +44,16 @@
   .product(default: 1)
 }
 
-#let set_nr_interactions(chip) = {
+// Compute the number of interactions performed by `chip` and
+// store it as metadata under the `<interaction_count>` label
+// with tag `chip.name`. This tag is overwritten by `name` when specified.
+#let set_nr_interactions(chip, name: none) = {
+  let chip-name = if name != none {
+      name 
+    } else {
+      chip.name    
+    }
+
   let constraints = chip
     .constraints
     .values()
@@ -73,7 +82,9 @@
 
     let total-nr-interactions = nr-direct-interactions + nr-indirect-interactions
 
-    [#metadata((chip.name: total-nr-interactions)) <interaction_count>]
+    let entry = (:)
+    entry.insert(chip-name, total-nr-interactions)
+    [#metadata(entry) <interaction_count>]
   }
 }
 

From a823099c4eedf3f2a2df82b825573bd09aa5bdb1 Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Tue, 31 Mar 2026 15:18:37 +0200
Subject: [PATCH 6/9] spec/interaction-counter: drop silent lookup fails

---
 spec/chip.typ | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/spec/chip.typ b/spec/chip.typ
index eb65c5128..2634c3fa1 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -74,7 +74,11 @@
     let nr-indirect-interactions = template-constraints
       .map(c => {
         let iter-size = get_interaction_count(c)
-        let template-interactions = lookup-table.at(c.tag, default: 0)
+        assert(
+          c.tag in lookup-table, 
+          message: "cannot find interaction_count for " + repr(c)
+        )
+        let template-interactions = lookup-table.at(c.tag)
 
         iter-size * template-interactions 
       })
@@ -90,7 +94,9 @@
 
 #let get_nr_interactions(chip) = {
   context {
-    query(<interaction_count>).map(c=>c.value).sum().at(chip.name)
+    let lut = query(<interaction_count>).map(c=>c.value).sum(default: (:))
+    assert(chip.name in lut, message: "no interaction_count specified for " + repr(chip.name))
+    lut.at(chip.name)
   }
 }
 

From fcbd219d681b7f9122f674d1dbec3f4562168c0b Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Tue, 31 Mar 2026 15:23:44 +0200
Subject: [PATCH 7/9] spec/interaction-counter: remove superfluous code

---
 spec/is_bit.typ | 1 -
 1 file changed, 1 deletion(-)

diff --git a/spec/is_bit.typ b/spec/is_bit.typ
index bb2690afc..1ed5e6284 100644
--- a/spec/is_bit.typ
+++ b/spec/is_bit.typ
@@ -8,7 +8,6 @@
 #show: book-page(chip.name)
 
 #set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
 
 #let is_bit = raw(chip.name)
 

From 6dae904025dd579f44dee8945258e462f7a899eb Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Wed, 1 Apr 2026 16:03:59 +0200
Subject: [PATCH 8/9] spec/interaction_count: merge getter and setter

---
 spec/add.typ    |  5 ++---
 spec/branch.typ |  6 ++----
 spec/chip.typ   |  3 ++-
 spec/cpu.typ    |  6 ++----
 spec/dvrm.typ   |  6 ++----
 spec/ecall.typ  |  9 +++------
 spec/is_bit.typ |  2 +-
 spec/load.typ   |  6 ++----
 spec/lt.typ     |  6 ++----
 spec/memw.typ   | 12 ++++--------
 spec/mul.typ    |  6 ++----
 spec/neg.typ    |  5 ++---
 spec/shift.typ  |  6 ++----
 spec/sign.typ   |  6 +++---
 14 files changed, 31 insertions(+), 53 deletions(-)

diff --git a/spec/add.typ b/spec/add.typ
index a41fd37b8..7fb5cd43a 100644
--- a/spec/add.typ
+++ b/spec/add.typ
@@ -1,15 +1,14 @@
 #import "/book.typ": book-page, et
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table, set_nr_interactions, get_nr_interactions,
+#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table, set_nr_interactions, compute_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/add.toml", config)
 
 #show: book-page(chip.name)
 
-#set_nr_interactions(chip)
 #set_nr_interactions(chip, name: "SUB")
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 #let add = raw(chip.name)
 #let sub = raw("SUB")
diff --git a/spec/branch.typ b/spec/branch.typ
index 6a4d4feb1..ee406f2e0 100644
--- a/spec/branch.typ
+++ b/spec/branch.typ
@@ -3,8 +3,7 @@
 #import "/chip.typ": (
   render_chip_assumptions,
   render_chip_column_table,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   total_nr_variables,
   total_nr_instantiated_columns,
   render_constraint_table,
@@ -22,8 +21,7 @@ The #branch chip computes the target address of a branching instruction.
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The #branch chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/chip.typ b/spec/chip.typ
index 2634c3fa1..78247d35a 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -92,7 +92,8 @@
   }
 }
 
-#let get_nr_interactions(chip) = {
+#let compute_nr_interactions(chip) = {
+  set_nr_interactions(chip)
   context {
     let lut = query(<interaction_count>).map(c=>c.value).sum(default: (:))
     assert(chip.name in lut, message: "no interaction_count specified for " + repr(chip.name))
diff --git a/spec/cpu.typ b/spec/cpu.typ
index 715b9d64d..c5d693782 100644
--- a/spec/cpu.typ
+++ b/spec/cpu.typ
@@ -5,8 +5,7 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   render_constraint_table,
   render_chip_padding_table,
 )
@@ -23,8 +22,7 @@ It bases its decisions on the entry of the `DECODE` table (@decode) correspondin
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The #cpu chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/dvrm.typ b/spec/dvrm.typ
index 9a420d056..9afc3ed7f 100644
--- a/spec/dvrm.typ
+++ b/spec/dvrm.typ
@@ -4,8 +4,7 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   render_constraint_table,
   render_chip_padding_table,
   render_chip_assumptions
@@ -23,8 +22,7 @@ The #dvrm chip provides division and remainder functionality, both signed and un
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The #dvrm chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/ecall.typ b/spec/ecall.typ
index 754172bac..2a7759876 100644
--- a/spec/ecall.typ
+++ b/spec/ecall.typ
@@ -4,8 +4,7 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   render_constraint_table,
   render_chip_assumptions,
   render_chip_padding_table,
@@ -34,8 +33,7 @@ where `A0`-`A7` are symbolic names for the registers `x10`-`x17`
 == Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_halt_interactions = get_nr_interactions(chip)
+#let nr_halt_interactions = compute_nr_interactions(chip)
 
 The #halt chip leverages #nr_variables variable, spanning #nr_columns columns and leverages #nr_halt_interactions interaction(s):
 #render_chip_column_table(chip, config)
@@ -80,8 +78,7 @@ As such, no padding is defined.
 == Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_commit_interactions = get_nr_interactions(chip)
+#let nr_commit_interactions = compute_nr_interactions(chip)
 
 The #commit chip leverages #nr_variables variables, spanning #nr_columns columns and leverages #nr_commit_interactions interactions:
 #render_chip_column_table(chip, config)
diff --git a/spec/is_bit.typ b/spec/is_bit.typ
index 1ed5e6284..53a466501 100644
--- a/spec/is_bit.typ
+++ b/spec/is_bit.typ
@@ -1,6 +1,6 @@
 #import "/book.typ": book-page
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table, render_constraint_table, set_nr_interactions, get_nr_interactions,
+#import "/chip.typ": render_chip_column_table, render_constraint_table, set_nr_interactions
 
 #let config = load_config()
 #let chip = load_chip("src/is_bit.toml", config)
diff --git a/spec/load.typ b/spec/load.typ
index 8d1f61fdc..e7d6d3da5 100644
--- a/spec/load.typ
+++ b/spec/load.typ
@@ -5,8 +5,7 @@
   render_chip_column_table,
   render_chip_padding_table,
   render_constraint_table,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   total_nr_instantiated_columns,
   total_nr_variables,
 )
@@ -23,8 +22,7 @@ It delegates low-level memory handling to the `MEMW` chip (@memw).
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The #load chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/lt.typ b/spec/lt.typ
index 763227e53..c9e700310 100644
--- a/spec/lt.typ
+++ b/spec/lt.typ
@@ -7,8 +7,7 @@
   render_constraint_table,
   total_nr_instantiated_columns,
   total_nr_variables,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
 )
 
 #let config = load_config()
@@ -22,8 +21,7 @@ The #lt chip constrains an indicator bit for the less-than relation, signed or u
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The #lt chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/memw.typ b/spec/memw.typ
index 2a77287b6..fb5c93e90 100644
--- a/spec/memw.typ
+++ b/spec/memw.typ
@@ -5,8 +5,7 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   render_constraint_table,
   render_chip_padding_table
 )
@@ -26,8 +25,7 @@ in order to satisfy the design of the memory argument (@memory).
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_memw_interactions = get_nr_interactions(chip)
+#let nr_memw_interactions = compute_nr_interactions(chip)
 
 The #memw chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_memw_interactions interaction(s):
 #render_chip_column_table(chip, config)
@@ -77,8 +75,7 @@ The table can be padded to the next power of two with the following value assign
 
 #let alignedchip = load_chip("src/memw_aligned.toml", config)
 #let aligned = raw(alignedchip.name)
-#set_nr_interactions(alignedchip)
-#let nr_aligned_interactions = get_nr_interactions(alignedchip)
+#let nr_aligned_interactions = compute_nr_interactions(alignedchip)
 
 When a memory access happens at an address with proper alignment for its access size
 (i.e., adding the access size to `base_address`'s lowest limb does not overflow), 
@@ -125,8 +122,7 @@ Note moreover that this chip does not guard against misaligned register access f
 == Columns
 #let nr_variables = total_nr_variables(register_chip)
 #let nr_columns = total_nr_instantiated_columns(register_chip, config)
-#set_nr_interactions(register_chip)
-#let nr_memw_r_interactions = get_nr_interactions(register_chip)
+#let nr_memw_r_interactions = compute_nr_interactions(register_chip)
 
 The #reg chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_memw_r_interactions interactions:
 #render_chip_column_table(register_chip, config)
diff --git a/spec/mul.typ b/spec/mul.typ
index 77d1cca43..479c2f32d 100644
--- a/spec/mul.typ
+++ b/spec/mul.typ
@@ -4,8 +4,7 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   render_constraint_table,
   render_chip_assumptions,
   render_chip_padding_table,
@@ -24,8 +23,7 @@ as well as providing access to the low and high halfs of the multiplication resu
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The #mul chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/neg.typ b/spec/neg.typ
index bcab35cbf..b2f75117a 100644
--- a/spec/neg.typ
+++ b/spec/neg.typ
@@ -1,13 +1,12 @@
 #import "/book.typ": book-page, et
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table, set_nr_interactions, get_nr_interactions,
+#import "/chip.typ": render_chip_column_table, render_chip_assumptions, render_constraint_table, compute_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/neg.toml", config)
 #show: book-page(chip.name)
 
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 #let neg = raw(chip.name)
 
diff --git a/spec/shift.typ b/spec/shift.typ
index 3b3478705..f356122a3 100644
--- a/spec/shift.typ
+++ b/spec/shift.typ
@@ -4,8 +4,7 @@
   render_chip_column_table,
   total_nr_variables,
   total_nr_instantiated_columns,
-  set_nr_interactions,
-  get_nr_interactions,
+  compute_nr_interactions,
   render_constraint_table,
   render_chip_assumptions,
   render_chip_padding_table,
@@ -38,8 +37,7 @@ Here, `<<` and `>>` denote the _logical_ left and right shift operations, while
 = Columns
 #let nr_variables = total_nr_variables(chip)
 #let nr_columns = total_nr_instantiated_columns(chip, config)
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 The `SHIFT` chip is comprised of #nr_variables variables that are expressed using #nr_columns columns and leverages #nr_interactions interaction(s):
 #render_chip_column_table(chip, config)
diff --git a/spec/sign.typ b/spec/sign.typ
index 06e766d5f..9e727e0ac 100644
--- a/spec/sign.typ
+++ b/spec/sign.typ
@@ -1,13 +1,13 @@
 #import "/book.typ": book-page
 #import "/src.typ": load_config, load_chip
-#import "/chip.typ": render_chip_column_table,   render_chip_assumptions, render_constraint_table, set_nr_interactions, get_nr_interactions,
+#import "/chip.typ": render_chip_column_table, total_nr_variables, render_chip_assumptions, render_constraint_table, compute_nr_interactions,
 
 #let config = load_config()
 #let chip = load_chip("src/sign.toml", config)
 #show: book-page(chip.name)
 
-#set_nr_interactions(chip)
-#let nr_interactions = get_nr_interactions(chip)
+#let nr_variables = total_nr_variables(chip)
+#let nr_interactions = compute_nr_interactions(chip)
 
 #let sign = raw(chip.name)
 

From 27d9de10d003d4bd41e0d20da444363cd19f9d1d Mon Sep 17 00:00:00 2001
From: Erik Takke <erik.takke@3milabs.tech>
Date: Wed, 1 Apr 2026 16:16:15 +0200
Subject: [PATCH 9/9] spec/interaction_counter: clean up

---
 spec/chip.typ | 33 +++++++++++++--------------------
 1 file changed, 13 insertions(+), 20 deletions(-)

diff --git a/spec/chip.typ b/spec/chip.typ
index 78247d35a..8304717ff 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -25,7 +25,7 @@
 }
 
 // Given a constraint, compute the number of interactions it induces
-#let get_interaction_count(constraint) = {
+#let get_constraint_interaction_count(constraint) = {
   let iters = if "iters" in constraint {
     constraint.iters
   } else if "iter" in constraint {
@@ -37,7 +37,7 @@
   iters.map(i => {
     assert(
       i.len() == 3 and type(i.at(1)) == int and type(i.at(2)) == int,
-      message: "contains invalid iter: " + repr(i),
+      message: "invalid iter: " + repr(i),
     )
     i.at(2) - i.at(1) + 1
   })
@@ -48,10 +48,8 @@
 // store it as metadata under the `<interaction_count>` label
 // with tag `chip.name`. This tag is overwritten by `name` when specified.
 #let set_nr_interactions(chip, name: none) = {
-  let chip-name = if name != none {
-      name 
-    } else {
-      chip.name    
+  if name == none {
+      name = chip.name
     }
 
   let constraints = chip
@@ -61,41 +59,36 @@
 
   // nr. of direct interactions
   let nr-direct-interactions = constraints
-    .filter(c=>c.kind == "interaction")
-    .map(get_interaction_count)
+    .filter(c => c.kind == "interaction")
+    .map(get_constraint_interaction_count)
     .sum(default: 0)
   
-  let template-constraints = constraints.filter(c=>c.kind == "template")
+  let template-constraints = constraints.filter(c => c.kind == "template")
 
   context {
-    let lookup-table = query(<interaction_count>).map(x => x.value).sum(default:(:))
+    let lookup-table = query(<interaction_count>).map(x => x.value).sum(default: (:))
 
     // nr. of indirect interactions through templates
     let nr-indirect-interactions = template-constraints
       .map(c => {
-        let iter-size = get_interaction_count(c)
-        assert(
-          c.tag in lookup-table, 
-          message: "cannot find interaction_count for " + repr(c)
-        )
-        let template-interactions = lookup-table.at(c.tag)
+        assert(c.tag in lookup-table, message: "cannot find interaction_count for " + repr(c))
 
+        let template-interactions = lookup-table.at(c.tag)
+        let iter-size = get_constraint_interaction_count(c)
         iter-size * template-interactions 
       })
       .sum(default: 0)
 
     let total-nr-interactions = nr-direct-interactions + nr-indirect-interactions
 
-    let entry = (:)
-    entry.insert(chip-name, total-nr-interactions)
-    [#metadata(entry) <interaction_count>]
+    [#metadata((str(name): total-nr-interactions)) <interaction_count>]
   }
 }
 
 #let compute_nr_interactions(chip) = {
   set_nr_interactions(chip)
   context {
-    let lut = query(<interaction_count>).map(c=>c.value).sum(default: (:))
+    let lut = query(<interaction_count>).map(c => c.value).sum(default: (:))
     assert(chip.name in lut, message: "no interaction_count specified for " + repr(chip.name))
     lut.at(chip.name)
   }