At the moment, the following sections describe only those language features that are New or Enhanced relative to the Extended APL Standard, or that deserve special comment.
Syntax
 Strand Assignment: (A1 A2 ... An)←R
 Modified Assignment: Af←R
 Modify Strand Assignment: (A1 A2 ... An)f←R
 Hyperators: ∇ Z←L (LO (LH dhdo RH) RO) R
 Function/Operator/Hyperator Assignment: A←f, A←op1, A←op2
 Binding Strength: How Variables, Functions, Operators, Hyperators and other syntactic elements combine
 Sink: ←R
 Point Notation:
 Base — 16b10FFFF is a shorthand for 16⊥1 0 15 15 15 15 and 10b45v is a shorthand for 10⊥4 5 31.
 Euler — 2x3 is a shorthand for 2e^{3} or 2×(*1)*3 where e is Euler's Number (2.718281828459045...).
 Pi — 2p3 is a shorthand for 2π^{3} or 2×(○1)*3 where π is Archimedes' constant (3.141592653589793...).
 Gamma — 2g3 is a shorthand for 2γ^{3} where γ is EulerMascheroni's Constant (0.5772156649015329...).
 Hypercomplex — 2i3, 2J3 (both equal to 2+3×√¯1), 2ad3 (Angle in Degrees), 2ar3 (Angle in Radians), 2au3 (Angle in Unit Normalized), or 2ah3 (Angle in Half Unit Normalized) for a Complex number, 1i2j3k4 for a Quaternion number, and 1i2j3k4l5ij6jk7kl8 for an Octonion number.
 Rational — 2r3 is a shorthand for 2÷3 as a MultiplePrecision Integer/Rational number.
 VariablePrecision Floating — 2.3v is a shorthand for 2.3 as a MultiplePrecision Floating Point number.
 Ball Arithmetic — 2.3±1E¯17 is a shorthand for a Ball whose Midpoint and Radius are 2.3 and 1E¯17, respectively.
 Trains: e.g., avg←(+⌿ ÷ ≢) applies the functions to its argument(s) in a particular way (in this case, to compute the average of a numeric scalar or vector).
 Anonymous Functions/Operators/Hyperators: multiline grouping of one or more statements all enclosed in braces such as {(+⌿⍵)÷≢⍵}.
Primitive Functions
Name 
Symbol/Syntax 
Function Valence

Array Lookup 
L⍸R 
dyadic

Condense 
<[X] R 
monadic

Dilate 
>[X] R 
monadic

Expand 
L\[X] R 
dyadic

Find 
L⍷R 
dyadic

Index Generator 
⍳R 
monadic

Index Of 
L⍳R 
dyadic

Indexing 
R[L], R[L]←A, R[L]f←A, L⌷[X] R, L⍉R, L⊃R 
dyadic

Indices 
⍸R 
monadic

Matrix Inverse/Divide 
⌹R, L⌹R 
ambivalent

Mismatch 
L≢R 
dyadic

Partitioned Enclose 
L⊂[X] R 
dyadic

Primes 
πR, LπR 
ambivalent

Reshape 
L⍴R 
dyadic

Root 
√R, L√[X] R 
ambivalent

Sequence 
L..R 
dyadic

Sets 
L§R, L⊆R, L⊇R 
dyadic

Tally 
≢R 
monadic

Without 
L~R 
dyadic

where L is the Left argument, R is the Right argument, and [X] is an optional Axis value.
Primitive Operators
Name 
Symbol/Syntax 
Derived Function Valence

Axis 
{L} f[X] R, {L} (f op1[X]) R, {L} (f op2[X] g) R 
ambivalent

Combinatorial 
a‼ R 
monadic

Commute 
L f⍨ R ←→ R f L 
dyadic

Composition 
{L} f⍥g R 
ambivalent

Compose 
{L} f∘g R, (f∘b) R, a∘g R 
ambivalent/monadic

Convolution 
L f⍡g R 
dyadic

Determinant 
f.g R 
monadic

Duplicate 
f⍨ R ←→ R f R 
monadic

Mask 
L (a∘/) R, L (a∘⌿) R, L (a∘/[X]) R 
dyadic

Nth Derivative 
{L} f∆ R, {L} f∆∆ R, etc. 
ambivalent

Matrix 
{L} f⌻ R, ∘⌻ R 
ambivalent/monadic

Mesh 
L (a∘\) R, L (a∘⍀) R, L (a∘\[X]) R 
dyadic

Multisets 
{L} f⍦ R 
ambivalent

Null 
{L} f⊙ R 
ambivalent

Power 
{L} f⍣g R, {L} (f⍣b) R 
ambivalent

Rank 
{L} (f⍤[X] b) R 
ambivalent

Variant 
{L} (f⍠b) R 
ambivalent

where {L} is an optional Left argument, R is the Right argument, f and g represent Functions, a and b represent Variables, and [X] is an optional Axis value.
Primitive Hyperators
Name 
Symbol/Syntax 
Derived Function Valence

Transform 
f h⍑g R 
monadic

where {L} is an optional Left argument, R is the Right argument, f and g represent Functions, h represents a Function/Operator, and [X] is an optional Axis value.
Also, see Hyperators.
Datatypes
System Commands
System Commands provide features to the user of the APL system, separate from actual workspaces, variables or APL operators. These provide such features as accessing files, saving a workspace, and exiting the APL interpreter. The commands are not case sensitive, so )IN and )in do the same thing.
NARS2000 currently has the following system commands:
)BOX


Turn ON/OFF box around output

)CLEAR


Start a new session manager window with an empty workspace

)CLOSE

)COPY

)DROP

)EDIT


Create a new function in the workspace or edit an existing function

)ERASE


Delete a variable or function in the current workspace

)EXIT


Close down the interpreter and exit the program. Same as )OFF

)FNS

)FOP


Display functions, operators, and hyperators. Same as )FOPS

)FOPS

)HYP


Display hyperators only

)IN

)INASCII



)LIB

)LAOD


Alternative spelling of )LOAD

)LOAD


Load an existing workspace

)NEWTAB



System Variables and Functions