Dot products turn pairs of vectors into exact integers. The dot table shows the source vectors, a term-by-term walkthrough, and the resulting alignment scores.

highlighted = computed this step

The dot product

For two-dimensional vectors, u dot v is u1 times v1 plus u2 times v2. Because the coordinates are integers, the dot product is an integer alignment score under this chosen rule.

uv=u1v1+u2v2u\cdot v=u_1v_1+u_2v_2
Exact dot productsDots are recomputed from displayed vectors.Exact dot productsDots are recomputed from displayed vectors.exact dot productstie-break: lexicographically smallest word among max dot productsvectors:cat=(3,1); kitten=(2,1); car=(1,3)pairdotcat·kitten7cat·car6kitten·car5nearest to cat by dot=kitten (dot=7)

Term by term

The dot of cat=(3,1) with kitten=(2,1) is built one product at a time: 3 times 2 is 6, then 1 times 1 is 1. The running total goes 6 then 7, so cat dot kitten = 7, matching the dot table.

catkitten=32  +  11=6  +  1=7\text{cat}\cdot\text{kitten}=3\cdot2\;+\;1\cdot1=6\;+\;1=7
Dot product, term by termExact integer row-dot-column walkthrough of cat·kitten.u·v = Σ uᵢvᵢ (one scalar)Ac1c231·xentry21products3·2=6Σ=6+1·1=1Σ=7result 7u·v = 7one exact integer dot product on assigned toy embedding vectors; this does not claimlearned embeddings, does not claim meaning, and does not claim understanding

Three exact dots

The exact dots are cat dot kitten = 7, cat dot car = 6, and kitten dot car = 5. These are scores from the assigned coordinate geometry.

catkitten=7,catcar=6,kittencar=5\text{cat}\cdot\text{kitten}=7,\quad \text{cat}\cdot\text{car}=6,\quad \text{kitten}\cdot\text{car}=5
Exact dot productsDots are recomputed from displayed vectors.Exact dot productsDots are recomputed from displayed vectors.exact dot productstie-break: lexicographically smallest word among max dot productsvectors:cat=(3,1); kitten=(2,1); car=(1,3)pairdotcat·kitten7cat·car6kitten·car5nearest to cat by dot=kitten (dot=7)

Summary

The dot table is self-contained: it shows the source vectors and recomputes every dot from them. The next lesson uses those integer dots for an argmax.

dots 7,6,5\text{dots }7,6,5
Exact dot productsDots are recomputed from displayed vectors.Exact dot productsDots are recomputed from displayed vectors.exact dot productstie-break: lexicographically smallest word among max dot productsvectors:cat=(3,1); kitten=(2,1); car=(1,3)pairdotcat·kitten7cat·car6kitten·car5nearest to cat by dot=kitten (dot=7)