Projection Measurements

Two Directions Give Two Ledgers

The same tiny grid must satisfy both row and column projections. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Rows give one projection ledger

The two row sums are 3 and 7.

1+2=33+4=71+2=3\quad3+4=7
Projection imageRows and columns expose exact line-sum measurements.123437465

Columns give another projection ledger

The column sums are 4 and 6.

1+3=42+4=61+3=4\quad2+4=6
Projection imageRows and columns expose exact line-sum measurements.123437465