Symptom number

1

2

3

4

5

6

7

8

9
 
Episode


row 1

1

1

1

0

1

1

0

1

1

(mod 2)

1

row 2

0

1

0

0

1

0

0

1

1

(mod 2)

0

row 3

0

0

0

1

0

0

0

1

0

(mod 2)

0

row 4

1

1

0

1

1

0

1

0

1

(mod 2)

1

row 5

0

1

1

1

0

0

0

0

1

(mod 2)

0

row 6

1

1

1

0

1

1

0

0

1

(mod 2)

1

row 7 (= row 4)

1

1

0

1

1

0

1

0

1

(mod 2)

1

row 8 (= row 2)

0

1

0

0

1

0

0

1

1

(mod 2)

1

row 9 (= row 5)

0

1

1

1

0

0

0

0

1

(mod 2)

1

row 10 (= row 4)

1

1

0

1

1

0

1

0

1

(mod 2)

1

Total sum

5

9

4

6

7

2

3

4

9
 
5

Average

0.5

0.9

0.4

0.6

0.7

0.2

0.3

0.4

0.9
 
0.5

 Examples for symptoms 1–9 in Criterion A having values of 0 or 1 are shown. Each row is an assessment during a session. Rows 3 and 5 are equivalent to row 1; i.e., row = row 3 = row 5. Additionally, row 4 = row 6 = row 7 = row 9 = row 10, and row 2 = row 8. The expression of these examples can be simplified as in Table 2. In this case, the order of ‘which items should be effective on the scale’, is A_{all(1–9)} = [1_{1}1_{2}1_{3}1_{4}1_{5}1_{6}1_{7}1_{8}1_{9}0
_{
10
}0
_{
11
}0
_{
12
}…] (mod 2); all symptoms 1–9 in Criterion A should be effective, and this could be reinterpreted as the result of the operation (selection for effectiveness) A_{all(1–9)} (= A_{(0→all(1–9))}) acting on the identity order A_{0} = [0_{1}0_{2}0_{3}0_{4}0_{5}0_{6}0_{7}0_{8}0_{9}0
_{
10
}0
_{
11
}0
_{
12
}…] (mod 2); i.e., A_{0} * A_{(0→all(1–9))} = A_{all(1–9)}. A_{0} could be also regarded as an undiagnosed state. The rows whose components are equivalent to each other are compressed in the earliest rows of Table 2 and are highlighted silver in Table 1. Additionally, the diagnosis is given in the extreme right column; rows 1, 4, 6, 7 and 10 meet Criterion A of a ‘major depressive episode’ and have a diagnosis value of 1 (whereas rows not meeting Criterion A have a value of 0)