Application: Monadic Comma-Bar

,.Y         (J)
If y is an atom, then ,.y is 1 1$y ; otherwise, ,.y is ,"_1 y , the table formed by ravelling each item of y .

commabar1 ← {⍬≡⍴⍵ : 1 1⍴⍵ ⋄ ,R ¯1 +⍵}

commabar2 ← {,R ¯1⍣(1+⍬≡⍴⍵) +⍵}

commabar3 ← ,R ¯1 ⍣ 2