# APL Crossword 5

1. The inverse of `+\`, i.e. the first difference of `V`
2. `1↓⌽1↓'[(A)]'`
3. `1⊥⍳4`
4. Accept numeric input; call it `NMV`
5. Negate the vector `MB` and show its running total, LIFO (last in, first out) basis
6. Given distinct values in `A`, return `⍳⍴A` without using `⍴`
7. Where `T` is found in `V`
8. `(R×11)⍴11/V`
9. The elements of `V`, capped at `99`
10. `3↑'(0∊3↑V)'')'`
11. `SN` is contained in…
12. The two row matrix `YM` of year and month numbers, converted to months since the year `0000`, for date arithmetic
13. If `SV` represents Scalar left argument, Vector right argument, what combination can cause `LENGTH ERROR` for scalar functions?
14. `(V×25)+(25×N>0)-(25×N<0)`
15. The magnitude of `K`
16. Outer product product
17. The location of `V`’s first `9`
18. Evaluated input as a vector
19. The opposite of `+/` (silly)
20. For scalar `MA`, `+/20⍴MA`
21. `10 13 16 19 … 34`
22. The number of elements in any array `V`
23. `(⍳5)∘.=(⍳5)`
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 `⎕NL 2`
7. Set A as the indices of the elements of the vector `NV`
8. The distinct values in the character vector `V`
9. A nice acronym for `⍳0`
10. If `N` is `1 9 9 2`, an expression that returns `1992`
11. The values of the matrix `M`, rounded to the nearest integer
12. If `VN=0`, return `⍳0`; but if `VN` is positive, return two elements of …
13. The number of `1`s in the vector …
14. `10⍴⍳M`, in origin 0
15. Add to each of the elements of `V` the numbers 1 to 5
16. Fido’s favourite variable name
17. The location in `V` of `27` and …
18. `(2/(2⍴(1⍴'()')))`
19. Are there some elements in …
20. The matrix `M` expressed as a vector, with a `0` after each row
21. `A` is true only if `A` is a nonscalar
22. `2*5`
23. `¯2↑'–(⍳9)'`
24. The most efficient expression that returns `1`