# Invertible
(⊑≡⊑⌾⊢) ⟨↕3,2,<"abc"⟩
3 (+≡+⌾⊣) 4
(¯2⊸↓ ≡ 2⊸↓⌾⌽) ↕6
(1⊸↓⌾⍉ ≡ 1⊸↓˘) ↕3‿3
7(⥊⌾(<˘)≡·<˘⁼⥊⟜(<˘))3‿3⥊↕9
"abcd" (⊣≡»⌾≍) ↕4
! % ⍉⌾≍ "abc"
(⌽∘|⊸/4‿¯3) ≡ ↕∘≠⊸-⌾(3⊸⌽)↕7

# Structural
# Monad
"bbcd" ≡ 1⊸+⌾⊑ "abcd"
(<∘- ≡ -⌾⊑) 4
(⌽⌾⊏ ≡ ⌽⊸≍˝) "abc"≍"def"
! % -⌾⊏ 4
1 ≡ "cd"‿"ab"⊸⊐⌾< "ab"
(0‿1+⌜0‿4‿2) ≡ ⍋∘⍋⌾⥊ "apl"≍"bqn"
2 (⌽⌾⥊ ≡ 12|+) ⥊⟜(↕×´)6‿2
↕∘≠⊸+{𝔽≡𝔽¨⌾↑} "abcde"
2⊸+{𝔽≡𝔽¨⌾↓} "abcde"
# Dyad
! % ↕∘≠⊸+⌾(10⊸⥊)↕6
(⌽⍒⌊2÷˜↕7) ≡ ⌽˘⌾(⌊‿2⥊⊢)↕7
¯1‿0‿1‿3 ≡ -⟜(+´÷≠)⌾(3⊸↑)↕4
"adcb" ≡ ⌽⌾(1⊸↓)"abcd"
5‿6‿3‿0 ≡ (5‿3‿1⌾(0‿0⊸⍉)4‿3⥊0) +´∘×⎉1‿∞ 1+↕3
"AbcD" ≡ ('A'-'a')⊸+⌾(1‿0‿0‿1⊸/)"abcd"
"AbcD" ≡ "ABCD"⊣⌾(1‿0‿0‿1⊸/)"abcd"
! % ↕∘≠⊸+⌾(2⊸/)↕5
(1⊸⌽ ≡ 2⊸⌽⌾(2⊸/)) ↕5
"bdca" ≡ 1⊸⌽⌾(1‿3‿0⊸⊏)"abcd"
! % 1⊸⌽⌾(1‿3‿3‿0⊸⊏)"abcd"
((¯1⋆2∧⌜○(⌽0=↕)3)⊸× ≡ -⌾(1‿2⊑⊢))↕2‿3
((0‿3≍1‿2)⊸+ ≡ ⟨1,2‿3⟩⊸+⌾(⟨1‿0,⟨1‿1,0‿1⟩⟩⊸⊑))↕2‿2
# Compound
(1+↕3) ≡ 1⊸↓⌾(@⊢·⊑<)↕4
"210abc" ≡ ⌽⌾((2÷˜≠)⊸↑)"012abc"
"bac"‿'d' ≡ ⌽⌾(2↑⊑)"abc"‿'d'
(⌽¨⌾(<2‿3⊸⊏) ≡ ⌽⌾(2‿3⊸⊏)) "abcdef"
# Fills
! % ⌽⌾(1↓4↑⊢)"abc"

# Computational
3 % 1⊸+⌾-4
20 % ⌊0.5+ 4+⌾(⋆⁼)5
2 % ⊢⌾2 3
-2 % ⊢⌾(2∘-) 3
∘‿+ ≡ ⊢⌾∘‿+ 1