Combinators

A combinator is a function or operator that only refers to its arguments and operands without modifying them in any way. SymbolAPL expressionBird(1)TinyAPLDiagram

                I
              
              \mathrm I
            
          yIdentity⊣/⊢
            
              
                K
              
              \mathrm K
            
          xKestrel⊣
            
              
                κ
              
              \kappa
            
          yKite⊢
            
              
                W
              
              \mathrm W
            
          y F yWarbler⍨
            
              
                C
              
              \mathrm C
            
          y F xCardinal⍨
            
              
                B
              
              \mathrm B
            
          F (G y)Bluebird∘/⍤/⍥
            
              
                Q
              
              \mathrm Q
            
          G (F y)Queer⍛
            
              
                
                  B
                  1
                
              
              {\mathrm B}_1
            
          F (x G y)Blackbird⍤
            
              
                Ψ
              
              \Psi
            
          (G x) F (G y)Psi⍥
            
              
                S
              
              \mathrm S
            
          y F (G y)Starling⟜/⇽
            
              
                Σ
              
              \Sigma
            
          (F y) G yViolet Starling⊸/⇾
            
              
                D
              
              \mathrm D
            
          x F (G y)Dove∘/⟜
            
              
                Δ
              
              \Delta
            
          (F x) G yZebra Dove⍛/⊸
            
              
                Φ
              
              \Phi
            
          (F y) G (H y)Phoenix«»
            
              
                
                  Φ
                  1
                
              
              \Phi_1
            
          (x F y) G (x H y)Pheasant«»
            
              
                
                  D
                  2
                
              
              {\mathrm D}_2
            
          (F x) G (H y)Dovekie⊸ + ⟜
            
              
                P
              
              \mathrm P
            
          (y G x) F (x G y)Parrot(2)⸚
            
              
                N
              
              \mathrm N
            
          x F (x G y)Eastern Nicator⇽
            
              
                ν
              
              \mathrm \nu
            
          (x F y) G yWestern Nicator⇾

Additionally, some other primitives have combinator-like behavior: APL expressionTinyAPLDiagramn⍨n⍨F y⁖x G y⁖

Footnotes

  Some combinators have bird names, originating from To Mock a Mockingbird by Raymond Smullyan. Some of the bird names are taken from the Uiua combinator page.


  I made this one up.