**Note:**

The clues for the new crossword contain some APL characters. These are coded as APL2741 (available as a 45K download), and also with <CODE> tags. The mapping is compatible with both the APL2000 font and the current Dyalog font.

## Solution to APL Crossword from 15.2

## Crossword from 15.3

**Across**

1. The inverse of `+/`

, i.e. the first difference of `V`

6. `1‡²‡'[(A)]'`

9. `1ƒ¼4`

10. Accept numeric input; call it `NMV`

11. Negate the vector `MB`

and show its running total, `LIFO`

(last in, first out ) basis

13. Given distinct values in `A`

, return `¼½A`

without using `½`

14. Where `T`

is found in `V`

15. `(R§11)½11/V`

16. The elements of `V`

, capped at `99`

18. `3†'(0¹3†V)'')'`

19. `SN`

is contained in...

20. The two row matrix `YM`

of year and month numbers, converted to months since the year `0000`

, for date arithmetic

22. If `SV`

represents Scalar left argument, Vector right argument, what combination can cause `LENGTH ERROR`

for scalar functions?

23. `(V§25)+(25§N>0)-(25§N<0)`

25. The magnitude of `K`

27. Outer product product

28. The location of `V`

’s first `9`

31. Evaluated input as a vector

32. The opposite of `+/`

(silly)

33. For scalar `MA`

, `+/20½MA`

35. `10 13 16 19 ... 34`

39. The number of elements in any array `V`

40. `(¼5)°.=(¼5)`

**Down**

1. The fractions used to spread a value, given relative weights in the vector `V`

2. `¯1‡(¯1†V9),V9)`

3. `9 8 7 6 ... 1`

4. `~^/,B`

5. One more than `VN`

if any of `Y`

are true

6. The system command for `ŒNL 2`

7. Set A as the indices of the elements of the vector `NV`

8. The distinct values in the character vector `V`

12. A nice acronym for `¼0`

15. If `N`

is `1 9 9 2`

, an expression that returns `1992`

17. The values of the matrix `M`

, rounded to the nearest integer

18. If `VN=0`

, return `¼0`

; but if `VN`

is positive, return two elements of ...

20. The number of `1`

s in the vector ...

21. `10½¼M`

, in origin 0

24. Add to `EACH`

of the elements of `V`

the numbers 1 to 5

26. Fido’s favourite variable name

28. The location in `V`

of `27`

and ...

29. `(2/(2½(1½'()')))`

30. Are there some elements in ...

31. The matrix `M`

expressed as a vector, with a `0`

after each row

34. `___A`

is true only if `A`

is a nonscalar

36. `2*5`

37. `¯2†'–(¼9)'`

38. The most efficient expression that returns `1`

Reprinted with kind permission from Zark APL Tutor News, a quarterly publication of Zark Incorporated, 23 Ketchbrook Lane, Ellington, CT06029, USA