The History of Mathematical Proof in Ancient Traditions

378 jens Høyrup

Rev.

1. 3°30 ́, the made-hold,

2. from one tear out,

3. to one append.

4. Th e fi rst is 12, the second is 5.

5. 12 is the igibûm , 5 is the igûm.

Th e procedure can be followed in Figure 11.7 ; the text is another

instance of self-evident validity, and only diff ers from those discussed

under this perspective in having the sides and the area of the rectan-

gle represent numbers and not just themselves. Th e interesting point is

found in Rev. 2–3. In cases where there is no constraint on the order, the

Babylonians always speak of addition before subtraction. Here, however,

the 3°30 ́ that is to be added to the left of the gnomon (that is, to be put

Figure 11.7 Th e procedure of YBC 6967.

7

60

i g û m

i g i b û m

i g û m

1

(^82)
12
12
8
12
3
5
1
(^32)
121 / 4