Task
BNF Grammar
You are encouraged to solve this task according to the task description, using any language you may know.

4D

ALGOL 60

ALGOL 68

APL

AWK

ActionScript

Ada

Agda2

AmigaE

AppleScript

Assembly

AutoHotkey

BASIC

Bc

Befunge

Brainf***

C

C#

C++

Caml

Clean

Clojure

Cobol

ColdFusion

Common Lisp

Component Pascal

Coq

D

DOS Batch File

Dc

Delphi

E

EC

ELLA

ESQL

Eiffel

Emacs Lisp

Erlang

F

F#

FALSE

FP

Factor

Fan

Forth

Fortran

GAP

Gnuplot

Groovy

HaXe

Haskell

IDL

Icon

Io

J

JSON

JScript.NET

Java

JavaScript

JoCaml

Joy

JudoScript

Korn Shell

LSE64

LaTeX

LabVIEW

Lisaac

Lisp

Logtalk

LotusScript

Lua

Lucid

M4

MAXScript

MIRC Scripting Language

MS SQL

Make

Maple

Mathematica

Maxima

Metafont

Modula-3

NewLISP

Nial

OCaml

Oberon-2

Object Pascal

Objective-C

Octave

Omega

OpenEdge/Progress

Oz

PHP

PL/I

PL/SQL

Pascal

Perl

Pike

Plain TeX

Pop11

PostScript

PowerShell

Prolog

Python

Q

R

REXX

RapidQ

Raven

Rhope

Ruby

SAS

SETL

SMEQL

SNUSP

SQL

Scala

Scheme

Script3D

Seed7

Self

Slate

Smalltalk

Standard ML

TI-83 BASIC

TI-89 BASIC

Tcl

Toka

Tr

Transact-SQL

Twelf

UNIX Shell

UnixPipes

Unlambda

V

VBScript

Vedit macro language

Visual Basic

Visual Basic .NET

Visual Objects

Wrapl

XSLT

XTalk