⊗ — Outer product

Monadic operator. Keys: Alt-o m

X g⊗Y applies g to every pair. Two atoms call g directly. Array arguments supply the result shape ⍴X , ⍴Y.

5+⊗5               ⍝ 10
5+⊗⊂5              ⍝ ⊂10
1,⊗2               ⍝ 1 2
1 2+⊗10 20         ⍝ [11 21⋄12 22]
⍳3 =⊗ ⍳3           ⍝ [$t $f $f⋄$f $t $f⋄$f $f $t]

Array frames collect pair results as items. See inner product.

Inverse

With either argument fixed, X f⊗⁻¹ Y gives the argument whose outer product with X is Y.

1 2+⊗⁻¹1 2+⊗10 20   ⍝ 10 20