Chapter 6 of 11
72 Names as Sequences, Codes, and Lattices
The 72 Names unfold from three verses into a combinatorial object: a set of fixed‑length sequences over a 22‑letter alphabet with internal structure. You will treat the Shem ha‑Mephorash as a code, a lattice, and a dataset for modeling.
From Verses to Combinatorics: What Are the 72 Names?
Goal of the Module
You will treat the traditional 72 Names as a mathematical object: a finite set of fixed‑length sequences over a 22‑letter alphabet, built from three verses in Exodus.
Historical Source
Commentators derive 72 three‑letter names from Exodus 14:19–21. Each verse has 72 consonantal letters. A specific layout and reading rule turns these letters into 72 triplets.
What You Will Learn
You will reconstruct the algorithm, encode the names as length‑3 sequences, define distances like Hamming distance, and view the set as a code and a small lattice or graph.
Step 1 – Model the Hebrew Alphabet as a 22‑Symbol Set
The Alphabet as a Set
We treat the 22 Hebrew letters as a finite symbol set A = {a1, a2, ..., a22}. The only thing that matters combinatorially is that there are 22 distinct symbols.
Practical Encodings
For computation, we often encode letters as integers 0–21 or as short strings. Integers make it easy to compute distances and visualize the 72 Names as points in A^3.
Step 2 – The Classical Construction Algorithm
Three 72‑Letter Verses
Let V1, V2, V3 be the consonantal texts of Exodus 14:19–21, each of length 72. We ignore spaces and vowels and only track the 72 letters in each verse.
The 3×72 Array
Write V1 left to right, V2 right to left under it, and V3 left to right under that. This creates a 3×72 array where each column holds one letter from each verse.
Forming the Triplets
For each column i = 1..72, read top to bottom: letter i of V1, then V2, then V3. Concatenate to form the i‑th three‑letter name. The result is 72 triplets.
Step 3 – A Toy Example of the Construction
Toy Alphabet Setup
Use a toy alphabet A = {A, B, C, D} and three short verses V1 = A B C D, V2 = B C D A, V3 = C D A B to mirror the real construction.
Arrange as 3×4 Array
Write V1 left to right, V2 right to left, V3 left to right, forming columns: (A,A,C), (B,D,D), (C,C,A), (D,B,B).
Resulting Triplets
Reading each column top to bottom yields four triplets: AAC, BDD, CCA, DBB. This is the same pattern used to build the 72 Names from Exodus.
Step 4 – Implementing the Construction in Code
You can encode the construction algorithm using a high‑level language like Python. This lets you treat the 72 Names as a dataset for analysis.
Below is a generic implementation using strings. You can adapt it to real Hebrew text or to toy examples.
```python
Example: construct names from three equal-length strings
def construct_triplets(v1: str, v2: str, v3: str):
"""Return list of 3-letter names from three equal-length verses.
v1, v2, v3 are strings of symbols (no spaces)."""
assert len(v1) == len(v2) == len(v3), "Verses must have same length"
n = len(v1)
Step 1: V1 left-to-right is already v1
row1 = v1
Step 2: V2 right-to-left
row2 = v2[::-1]
Step 3: V3 left-to-right is already v3
row3 = v3
triplets = []
for i in range(n):
column i: row1[i], row2[i], row3[i]
triplet = row1[i] + row2[i] + row3[i]
triplets.append(triplet)
return triplets
Toy example from the previous step
v1 = "ABCD"
v2 = "BCDA"
v3 = "CDAB"
names = construct_triplets(v1, v2, v3)
print(names) # Output: ['AAC', 'BDD', 'CCA', 'DBB']
```
Step 5 – Viewing the 72 Names as a Code in A^3
Names as Vectors
Each three‑letter name is a vector of length 3 over the alphabet A. The ambient space is A^3, the set of all possible triples of letters.
Defining a Code
A code is any subset C of A^n. Here, C is the set of 72 Names inside A^3. Codewords are the individual triplets.
Questions to Ask
Once we see the names as codewords, we can study distances, similarities, and symmetries, just as in coding theory and graph theory.
Step 6 – Distances and Neighborhoods (Hamming Distance)
Hamming Distance
For two triplets x and y, the Hamming distance d_H(x, y) is the number of positions where x and y have different letters. It ranges from 0 to 3.
Examples of d_H
ABC vs ABC: dH = 0. ABC vs ADC: dH = 1. ABC vs DCA: d_H = 3. This gives a clear, countable measure of similarity.
Neighborhoods and Graphs
Define neighbors as names at distance 1. Build a graph with 72 vertices, connecting two names if their Hamming distance is 1. This encodes adjacency.
Step 7 – Quick Distance and Neighborhood Exercise
Use this short exercise to internalize Hamming distance and neighborhood ideas.
- Suppose your alphabet is `{A, B, C}` and you have the following 4 names:
- N1 = A B C
- N2 = A C C
- N3 = B B C
- N4 = B C A
a) Compute the Hamming distance between N1 and each of the others.
b) Which names are in the radius‑1 neighborhood of N1 (distance ≤ 1)?
- Now imagine these 4 names are your entire code C.
a) Draw a simple graph (even in your head) with vertices {N1, N2, N3, N4}.
b) Add an edge between two vertices if their distance is 1.
c) Which vertex has the highest degree (most neighbors)?
Reflect: in the real 72‑Name set, some names will be more central (many neighbors) and some more isolated (few neighbors). This structure is what you will later treat as a lattice or graph of names.
Step 8 – From Code to Lattice and Graph Structures
A^3 as a Grid
Think of A^3 as a 22×22×22 grid. Each axis is a letter position in the triplet. Every point is a possible name; the 72 Names are 72 selected points.
Graph and Lattice Views
As a graph: connect points at Hamming distance 1. As a lattice: impose an order on A and use coordinatewise comparison to define a partial order on A^3.
Names as a Dataset
Treat the 72 Names as a data cloud. You can study letter frequencies, clusters of similar names, and the centrality of each name in the adjacency graph.
Step 9 – Check Your Understanding
Answer this question to verify that you understand the core ideas.
Which of the following best describes the 72 Names in this module's framework?
- A random selection of 72 triplets from all possible A^3 sequences
- A deterministically constructed subset of A^3 that can be treated as a code with a Hamming distance and an induced graph structure
- A continuous geometric object in 3‑dimensional Euclidean space
- A set of variable‑length sequences over an infinite alphabet
Show Answer
Answer: B) A deterministically constructed subset of A^3 that can be treated as a code with a Hamming distance and an induced graph structure
The 72 Names are built by a fixed algorithm from three 72‑letter verses, so they form a deterministic subset of A^3. We then equip A^3 with Hamming distance, view the 72 Names as codewords, and study the induced graph and lattice structures. They are not random, continuous, or variable‑length.
Step 10 – Key Term Review
Use these flashcards to review the core concepts from this module.
- Alphabet A (in this module)
- The 22‑letter Hebrew consonantal alphabet, abstracted as a finite symbol set {a1, ..., a22}. Only the cardinality and distinctness of symbols matter for the combinatorics.
- 72 Names (Shem ha‑Mephorash)
- A classical set of 72 three‑letter sequences derived from Exodus 14:19–21 by arranging the verses in alternating directions and reading columns top to bottom.
- Code (subset of A^n)
- A set C of fixed‑length sequences (codewords) drawn from the ambient space A^n. Here, the 72 Names form a code C ⊆ A^3.
- Hamming Distance
- A metric on fixed‑length sequences that counts the number of positions where two sequences differ. Used to define similarity and neighborhoods among names.
- Neighborhood (radius‑1)
- For a codeword x, the set of codewords y such that the Hamming distance d_H(x, y) is at most 1. Often used to define adjacency in a graph.
- Lattice / Ordered Structure on A^3
- A view of A^3 where an order is imposed on A and extended coordinatewise, giving a finite lattice in which the 72 Names occupy specific positions.
Key Terms
- A^3
- The Cartesian product A × A × A, the set of all length‑3 sequences over the alphabet A; the ambient space for the 72 Names in this module.
- Code
- In coding theory, a subset C of A^n consisting of codewords (fixed‑length sequences) used for representation, transmission, or structure.
- Alphabet A
- The abstract 22‑symbol set representing the Hebrew consonantal letters; used as the base set for forming sequences.
- Neighborhood
- The set of points within a specified distance (e.g., Hamming distance ≤ 1) of a given point in a metric space.
- Hamming Distance
- A metric on fixed‑length sequences that equals the number of positions at which two sequences differ.
- Lattice (order‑theoretic)
- A partially ordered set in which any two elements have a greatest lower bound (meet) and least upper bound (join); finite powers A^n can be given such a structure.
- 72 Names (Shem ha‑Mephorash)
- A classical list of 72 three‑letter sequences derived algorithmically from Exodus 14:19–21 by arranging and reading the verses columnwise.