Open topic with navigation
If Y is a name of a defined function or operator, R is a simple character matrix. The first row of R is the function or operator header. Subsequent rows are lines of the function or operator. R contains no unnecessary blanks, except for leading indentation of control structures, trailing blanks that pad each row, and the blanks in comments. If Y is the name of a variable, a locked function or operator, an external function, or is undefined, R is an empty matrix whose shape is 0 0.
∇R←MEAN X ⍝ Arithmetic mean  R←(+/X)÷⍴X  ∇ +F←⎕CR'MEAN' R←MEAN X ⍝ Arithmetic mean R←(+/X)÷⍴X ⍴F 2 30
The definition of ⎕CR has been extended to names assigned to functions by specification (←), and to local names of functions used as operands to defined operators.
If Y is a name assigned to a primitive function, R is a one-element vector containing the corresponding function symbol. If Y is a name assigned to a system function, R is a one element nested array containing the name of the system function.
PLUS←+ +F←⎕CR'PLUS' + ⍴F 1 C←⎕CR C'C' ⎕CR ⍴C'C' 1
∇R←CONDITION (FN1 ELSE FN2) X  →CONDITION/L1  R←FN2 X ⋄ →0  L1:R←FN1 X  ∇ 2 ⎕STOP 'ELSE' (X≥0) ⌊ ELSE ⌈ X←¯2.5 ELSE X ¯2.5 ⎕CR'FN2' ⌈ →⎕LC ¯2
If Y is a name assigned to a derived function, R is a vector whose elements represent the arrays, functions, and operators from which Y was constructed. Constituent functions are represented by their own ⎕CRs, so in this respect the definition of ⎕CR is recursive. Primitive operators are treated like primitive functions, and are represented by their corresponding symbols. Arrays are represented by themselves.
BOX←2 2∘⍴ +F←⎕CR'BOX' 2 2 ∘⍴ ⍴F 3 ]display F .→----------. | .→--. | | |2 2| ∘ ⍴ | | '~--' - - | '∊----------'
If Y is a name assigned to a defined function, R is the ⎕CR of the defined function. In particular, the name that appears in the function header is the name of the original defined function, not the assigned name Y.
AVERAGE←MEAN ⎕CR'AVERAGE' R←MEAN X ⍝ Arithmetic mean R←(+/X)÷⍴X