< — Sort up / Less

Function. Ranks: ∞ monadic, 0 0 dyadic

<Y sorts the major cells of Y ascending, as [⍋Y]⌷Y does. Ties keep their order.

<30 10 20           ⍝ 10 20 30
<"banana"           ⍝ "aaabnn"
<[3 1⋄1 2⋄2 0]  ⍝ [1 2⋄2 0⋄3 1]

X<Y tests X < Y for reals. Pervasive; tolerant.

1 2 3<2            ⍝ $t $f $f

See > to sort down, and ⍋ for the indices that sort.