⌝ — Outer productX 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 ⍝ 2 2⍴11 21 12 22
(⍳3)=⌝⍳3 ⍝ 3 3⍴1x 0x 0x 0x 1x 0x 0x 0x 1x
Array frames collect pair results as items. See inner product.