Automatically resizes dimensions to make fit the figure in the canvas.

Grammar format

A valid symbol is a string that starts with an alphabet and then has any number of alphabets or digits.

Production consist of the symbol to be expanded followed by a : then a sequence of symbols each separated by a whitespace. Sample in the form

SYM : S1 S2 ... Sn

Logo Commands

• FD x

Draws a line x units in length forward.

• BK x

Draws a line x units backwards.

• COLOR x

Sets the color of line drawn to x.

• RT x

Turns right by x degrees

• LT x

Turns left by x degrees

• PUSH

Saves the turtle state in the stack.

• POP

Pops the stack into the turtle's state.

• REPEAT num (cmd)

Repeats the command cmd, num times. cmd must be parenthesized.

• DO (cmd1) ... (cmdn)

Executes the commands cmd1 to cmdn in sequence. Each command must be parenthesized.

Draw commands are written in the form,

SYM = <logo command>

Check out the presets.