>> << Ndx Usr Pri Phr Dic Rel Voc !: wd Help Phrases

# 2H. Gerunds

The phrases included here illustrate the following uses of gerunds:

- Insertion
- Case statement
- Recursion
- Power

`m0=: horner=: +`*/` | `m0 a,x,b,x,c` is `(a,b,c)p.x`
`m1=: grid=: +`(*i.)/` | `grid b,s,n` From `b` in `n s-`steps
`m2=: case1=: _1:`%:`*:@.*"0` | Sqr, _1, or sq root if neg, zero, or pos
`d3=: sort=: /:~@]`(\:~@])@.[` | Sort up or down for left 0 or 1
`v4=: cases=: case1 : sort` | Ambivalent function
`a5=: sel=: 1 : '] #~ ] x. {.'` | Selection for Quicksort
`m6=: qs=: ] ` ($:@(<sel), =sel, $:@(>sel)) @. (1:<#)` | Quicksort defined recursively
`m7=: (0&,+,&0)^:([ `1:)` | Binomial coefficients (gerundial power)

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